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A MODEL OF THE EFFECTS OF INTRINSIC, STIMULUS, SENSORY, AND HORMONAL VARIABLES 0N 'IHE SEXUAL BEHAVIOR AND RELATED PENILE CONDITION AND SHEEIEIQII} PLASMA HORMONE LEVELS OF THE MALE RAT By Maurice John Dwyer III A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Zoology 1982 \- '- uu. us mix ABSTRACT .A MODEL OF THE EFFECTS OF INTRINSIC, STIMULUS, SENSORY, AND HORMONAL VARIABLES ON THE SEXUAL BEHAVIOR AND RELATED PENILE CONDITION AND SYSTEMIC PLASMA HORMONE LEVELS OF THE MALE RAT By Maurice John Dwyer III A comprehensive organization of the effects on male sexual behavior was developed to describe the empirical state of that behavioral know- ledge, to coalesce the complex of male sexual behavior measures, and to reflect on the limits of the current theoretic. The empirical model Icontains calculated mathematical or logical relationships between the intrinsic, stimulus, sensory, and hormone treatment variables and the behavioral, penile, or plasma hormone variables. The model responds to any combination of the 112 treatment variables and provides values for eight behavioral measures (IL, IF, EL, PEI, EF, PE, PI, 34) and the as- sociated two penile measures (papillae & weight) and three serum hormone concentrations (T, LH, FSH). A rank index of the data based reliability of each output for each behavioral measure is included. Comparison across the various treatment effects demonstrated con- sistent relationships between current theoretical mechanisms and the behavioral measures, especially within variable classes. The theoreti- cal copulatory mechanisms were reflected in the IF and EL, the arousal .mechanism in the ML, IL, and.PEI, and the satiety mechanism by the EF and.PE. Most of the behavioral measures correlated significantly with one another. The IL, EL, and PEI were positively correlated, and the EF correlated negatively. The IF and the PE-PI did not correlate well with Maurice John Dwyer III the others, but the IF was the most stable measure and the PE-PI was the most sensitive, reflecting sexual behavior only as a whole. A composite measure of male sexual behavior remains a possibility, but the correla- tions and consistency among the treatment variable effects was not strong enough to establish clear mathematical relations. A survey of the effects of the treatment variables indicated the need for additional theoretical constructs: a sensory integrator, a penile component, and hormonal state elements. The sensory integrator had both quantitative and qualitative stimulus and sensory organ aspects. The penile component was strongly dependent on androgens for its promin- ent support of copulation. The hormones acting primarily on peripheral tissues, like DHT, maintained the operation of copulatory but not arousal mechanisms: hormones acting centrally, like estradiol, main- tained arousal and not the copulatory mechanisms. Copyright by MAURICE JOHN DRYER 1982 ACKNOWLEDGMENTS My thanks go to my co-chairmen, Lynwood.G. Clemens for forbearance in the face of contention and James A. Resh for being there in times of need, and my committee members, John A. King and Erik D. Goodman, and .John.H. Fitch for their involvement and consideration. The computer funds for the model from the MSU Department of Electrical Engineering and Systems Science are appreciated. My special Thanks go to my wife, Joyce , for her continuous support. 111 TABLE OF CONTENTS LISTOFTABLES-..................... LISTOFFIGURES ..................... CHAPERlIntroduction................. CHAPTER 2 Behavioral and Testing Parameters . . . . . . . 2.1 The Organization of Male Rat Sexual Behavior . . 2.2 Experimental Testing Parameters. . . . . . . . . CHAPTER 3 Equation Generation and Modeling Procedures . . 3.1Introduction.................. 3.2 Procedures for Single Data Points . . . . . . . . 3.3EquationProcedures............... 3.4 Straight Linear Approximations . . . . . . . . . CHAPTER“ Model Structure andPreparation . . . . . . . . 1+.1 The Basic Structure of the Model . . . . . . . . 4.2 ModelingProcedures................ 4.3 DiagnosticPreparation ............. ll-ADiagnosticProgram............... 4.SUserInformation................ arms 5 Effects on the Post-Ejaculatory Interval (PEI) 5.1 Introduction and Description . . . . . . . . . . 5.2 Effect of Successive PEIs . . . . . . . . . . . . 5.38trainDifferences............... 5011' Effects Of Age 0 I O O O O O O O O O O I O O O 0 iv Page vii 10 22 23 29 1+1 5. 87 90 Table of Contents (cont'd) Page 5.5 TheTimeofTesting..................96 5.6 TheTimeBetweenTests(TBT).............. 99 5.? Sexual Experience Effects . . . . . . . . . . . . . . . 102 5.8 EarlyHousingEffects .................. 103 5.9 Introduction to Experimental Effects . . . . . . . . . . 104 5.10 Enforced Intromission Intervals . . . . . . . . . . . . 104 5.11 EffectsofanEnforcedPEI............... 108 5.12 ChangeofFemaleStimulus...............110 5.13 ElectricShockStimulus................lll 5.14 Electroconvulsive Shock (ECS) . . . . . . . . . . . . . 113 5.15ConditioningEffects..................114 5.16GroupSexualTests...................116 5.17 Miscellaneous Stimulus Manipulations . . . . . . . . . . 116 5.18 Introduction to Sensory Organ Manipulations . . . . . . 118 5.19 Olfactory Bulbectomy (om) and Peripheral Anosmia . . . 118 5.20 TheEffectofBlinding.................120 5.21 The Effects of Penile Nerve Cuts (PNX) . . . . . . . . . 121 5.22 Hormone Variable Introduction . . ._ . . . . . . . . . . 122 5.23 Gonadal Hormone Treatment Effects . . . . . . . . . . . 124 5.24AndrogenEffects....................133 5.25 Endrocrine Glands - Adrenalectomy . . . . . . . . . . . 143 5.26DrugEffects......................143 5.27PEIComposite.....................151 CHAPLER 6 A Summarization of the Input - Output Variable Relationships-0000000000000.oooo157 6.1 Introduction......................157 6.2 IntromissionLatency(IL)................ 158 V Table of Contents (cont'd) Page 6.3 Intromission.Frequency . . . . . . . . . . . . . . . . . 167 6.4 Ejaculation.Latency . . . . . . . . . . . . . . . . . . 178 6.5 Ejaculation Frequency . . ... . . . . . . . . . . . . . 187 6.6 Mount, Intromission, and.E3aculation Response Ratios (M) O O C O C O C C O C O C C O C C C C C O O O 193 6.7 PenilePapillaeandWeights 216 6.8 Introduction to the Hormone Summaries . . . . . . . . . 226 6.9 Testosterone . . . . . . . . . . . . . . . . . . . . . . 228 6.10 ‘Luteinizing Hormone . . . . . . . . . . . . . . . . . . 241 6.11 Follicle Stimulating Hormone . . . . . . . . . . . . . . 255 CHAPTER 7 Theoretical Considerations .' . . . . . . . . . . . . . 266 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . 266 7.2 Theoretical and.Modeling Implications . . . . . . . . . . 267 7.3 A Composite Male Sexual Behavior'Measure? . . . . . . . . 289 APPENDIX A - The Input'Variables . . . . . . . . . . . . . . . . . 297 APENDIXB-StandardFunctions.................310 APPENDIX C - The Direction of Effect for the Behavioral.Measures in Response to the Input'Variables and the Direction for the Penile Measures with the Hormonal Variables are Included . . . . . . . . . 313 SEXUALM'IAVIORANDPENHEBIEIOGRAH'IY ............o 319 HomONE BIHJImRAHIY I O O O O O I O O O O O O O O O O O O O I I O 335 Table 2.1 2.2‘ 2.3 3.1 3.2 4.1 4.2 4.3 4.4 5.1 5.2 5.3 7.1 7.2 7.3 7.4 LIST OF TABLES The Shape and Dimensions of the Rat Sexual Behavior Test Amms I I I I I I I I I I I I I I I I I I I I I I I I The Frequency and Percentage of Studies Utilizing Various Estrogen Treatments With or Without Progesterone. . . The Average Reported Estrogen Dosages With and Without ProgeswroneI I I I I I I I I I I I I I I I I I I I I A Sample Calculation of a Multiple Study Average for the Effect of Castration on the PEI Ratio . . . . . . . . An Example of the Fit of a Standard Equation to Composite Dau I I I I I I I I I I I I I I I I I I I I I I I I I Factors For the Total Number of Studies and Points. . . . A Sample Calculation of the Numerical Reliability Value (NR) From the Six Measures of Reliability . . . . . . A Sample Calculation of a Reliability Rank From the Numerical Measure of Reliability (NR) . . . . . . . . ASampleInputVariableList. . . . . . . . . . . . . . . The Average Normal PEIl Values for Different Rat Strains. Deviations From Five Consecutive Model PEIs of Old Males. Shock/No Shock Ratios for PEIl_3. . . . . . . . . . . . . The E/c Ratios For Sensory Oblations of Sexually Experi- enced Males I I I I I I I I I I I I I I I I I I I I I Correlations Between the Behavioral Measures. . . . . . . Total Behavioral and Penile Measure Comparisons . . . . . The Number of Same and Opposite Direction of Effect (Same/Opposite) for Measure to Measure Comparisons OfAllVariableS.........e......... Vii Page _ 16 18 18 32 36 65 69 76 88 95 112 273 291 291 292 List of Tables (cont'd) Table ' Page 7.5 The Ratio of the Major Same or Opposite Measure Correspon- dence to the Total Possible Number of Comparisons . . . 292 7.6 Sensitivity Indicator: The Ratio of the Number of Signif- icant Effects to Total Treatment Conditions . . . . . . 293 V111 LIST OF FIGURES Figure 2.1 The Relation of Male Sexual Behavior Events and Duration MeasumSI I I I I I I I I I I I I I I I I I I I I I I I 3.1 Several Possible Distributions of Five E/C Ratio Points with Reported Statistical Significance. . . . . . . . . 3.2 Different Fits of Sample Data to a Standard Equation Form.. 3.3 Linear Approximations to Three Different Types of Data POthDiStributionSeoeeoooeoeeooeeoeo 4.1 TheBasicStructureoftheModel.............. 4.2 The Relationship of Data Points from Three Studies to the Model Values Utilized in the Calculation of Deviation valuBSI I I I I I I I I I I I I I I I I I I I I I I I I 4.3 General Diagram for the Diagnostic Subprograms. . . . . . . 4.4 Sample Model Output for a Normal Control Male Rat Group . . 5.1 The Relation of Strain Averages to the Calculated Model CurveforConsecu‘tivePEIS. o o o e e o o o e e e o o o 5.2 The PEI1 Mean and Standard Error for Five Rat Strains . . . 5.3 The Effect of Age on the PEI1 Model Ratio for Male Rats . . 5.4 The Relation of the Time Between Tests (TBT) to the E/C Ratio in Two PEI Categories; PEI1 and Consecutive mISGreaterfllaanlleo00000000000...o 5.5 The Response of the PEI Ratio to Enforced ICIs after One Intromission or after A11 Intromissions in an EjaculatorySeries................... 5.6 Comparison of the Model Generated Curve with the Individual PEI1 Castrate/Intact Ratios from Available Studies. . . 7.1 The Relationship of Hormone, Stimulus, Sensory, and Penile Components or Elements to the Arousal, Satiety, and BehavioralMechanisms................. ix Page 27 39 43 47 61 71 80 86 89 91 100 106 125 287 II- (I. 21‘. N“. :u’ N Vs“ ha:\: ‘\ I D a... v i ‘h Chapter 1 Introduction Models are not new to animal behavior, nor specifically to the sexual behavior of the male rat. In the past, Beach (21) postulated two control mechanisms for male sexual behavior, a sexual arousal mechanism (SAM), initiating and reinitiating mounts and intromission, and a cepulatory mechanism. The copulatory mechanism takes over with the attainment of an intromission. Consecutive intromissions serve to either cumulatively increase the copulatory excitation to an ejac- ulatory threshold level (quantal) or maintain a level of excitation over a period of time necessary for ejaculation to occur (temporal). Both the quantal and temporal theories have support (172). Sachs and Barfield (172) have refined these ideas to include changes in the capulatory excitation due to extended intervals between intromissions and have included an inhibitory process following ejaculation. All these concepts are the bases for computer models constructed by Freeman and McFarland (78) and Toates and O'Rourke (197), which produce overt sexual behavior output responses similar to those of an experimental rat group. Although the theory can partially explain the changes in sexual behavior under normal experimental testing, the assumed ”arousal" mechanism, postulated as a change in some central nervous system (CNS) activity, has not yet been anatomically or physiologically demonstrated. Because the concommitant CNS changes cannot be empirically defined, the arousal conceptualization has gained few 1 2 adherents. However, no other theoretical controlling mechanisms have been postulated. A.major shortcoming to the sexual behavior theory is its con- finement to normal sexual behavior. It is not immediately adaptable to the explanation of changes in behavior due to the influence of the variety of experimental variables altering sexual behavior. The influence of hormonal, sensory, stimulus, and behavioral variables are continually affecting the behavior under nonexperimental condi- tions but are controlled under experimental conditions. The effects of these variables have no direct input to the current theory or models. No theory of the mechanisms controlling sexual behavior will be adequate until the influences of the impinging variables can be incorporated. Because of this limitation, the computer models based on the arousal-copulatory mechanism also do not allow for the surrounding variables. . Therefore, to bypass the controversial arousal mechanism and incorporate the variables surrounding sexual behavior, an "empirical" computer model was developed. The ”empirical” type model was developed directly from a large data base, that was available for the sexual behavior of the male rat, but which was available for few other behaviors or species. The data base was condensed and analysed to defined mathematical and logical relationships between each experimental variable and sexual behavior measure. The relationship between the dosage of testosterone injected over a period of days and the time to attain the first intromission (IL) was an example. These defined relationships were then linked into a whole, relating all intrinsic, sensory, stimulus, and hormonal variables to each male m I" 54 ‘ Iv I; o u l I h .u‘ u... .bha :~4 ‘ h 1“; ly“ w. ‘w- «5*! he“, I .v- 1". sexual behavior variable. The empirical approach stands at the opposite.extreme from a purely theoretical model, like the recent computer models of sexual behavior. While the theoretical model assumes underlying principles, the empirical model only simulates the activity of the phenomenon, assuming nothing beyond the experimental data. The empirical approach basically assumes a "black box" between treatment and response, input and output. With sexual behavior, the black box is primarily the CNS. The theoretical model assumes basic structures within the black box, based on hypothesis or theory of controlling mechanism(s). The CNS, in this case, takes on defined functional operating structures, although not necessarily like the anatomical or physiological structure of the CNS. An empirical model is more descriptive than explanatory. Therefore, it serves mainly as the first stage toward the development and testing of new or improved theoretical models or points directions for future research. As a first stage, the empirical models have limitations, the'same limitations as the available body of research. In the case of male rat sexual behavior, the most noticeable limitation is the scarcity of information on interactions among experimental variables. The data are primarily those of the effect of experimental treatments of one variable upon the sexual responses represented by the several male behavioral measures. The interaction limitation calls for the simplest model structure. Therefore, the null hypothesis of no interaction (unless an interaction was defined in the experimental literature) was assumed. However, this was not a presumption of no interaction. Interactions :12 :' I’q"; '(d ' - .‘Q., a 44.. 4 would be expected, especially among closely related variables, such as between two sensory variables. But when no patterns of inter- relationship are available, parsimony is recommended. The nearly one hundred variables affecting sexual behavior and the immediate lack of a theoretic incorporating these variables required the tool of a computer. The volume and complexity of the relationships could not be handled intelligibly by linguistic or diagrammatic means. The concise math/logic structure utilized with computers serves well. Hopefully, this organized body of relation- ships can serve to point out interactions requiring further study and provide the behavioral patterns that components of future models should incorporate. '...the model can serve as a valuable integrating framework for behavioral data and as a guide for underlying physiological mechanisms.‘ (Sachs & Barfield (172), p. 147) In recent years, male rodent sexual behavior has been studied with waning fervor. This in large part may be due to the complexity of male behavior compared with the more unitary female sexual behavior. The male complex includes several measures of the frequency of response events and the temporal patterning of these events. No single measure emerges preeminent. Confusion persists in interpreting the importance to male sexual behavior, in its entirety, of differential changes in the measures under different experimental conditions. That a particular variable may change one measure and not others further confuses the picture. unquestionably, a singly, composite male measure responsive to a potential change in any of the .\- .Au . x . a n n .4. .P- - 01¢ a. e a u. a.» :- s. a eh. I . I u all 7 a 0 e a 3531‘ v fin. a ‘I H‘She 5 measures in current usage would simplify interpretation of effects and facilitate comparisons of male and female behavioral response. The possibility of a composite male measure can be assessed when the response of the multiple measures of sexual behavior can be observed over a variety of treatment variables. A wide range of variables is recommended, because each variable or class of variables (e.g., intrinsic, sensory, hormonal, etc.) could differentially affect each measure. To talk about male behavior as a single entity requires the establishment of consistent patterns of change for any treatment, not a new set of patterns, for particular variables or class of variables. For example, the intromission frequency (IF) is often unaffected when others, such as the intromission latency (IL), are altered (172). Potentially some male measures are redundant and those remaining could be associated into a mathematical composite. On the whole, an empirical model of male sexual behavior can serve two main functions. Standing by itself, it serves as a descriptive reservoir of the known effects of the hormonal, sensory, stimulus, behavioral, and intrinsic variables, that are represented by defined patterns of relationship. Secondly, it serves as a substrate for the development of theoretical models that help eludicate underlying functional principles and for the assessment of the interrelationship of the sexual behavioral measures. Chapter 2 Behavioral and Testing Parameters 2.1 The Organization of Male Rat Sexual Behavior The experimental measures of sexual behavior in the male rat are a combination of frequencies and latencies, of event and time. The mount, intromission, and ejaculation are the event measures. These events are organized hierarchically. A mount occurs when the male rises behind the female and grabs her by both flanks, following with palpitation of the female's flanks and pelvic thrusting. The female responds with a curvature of the back, lordosis, and deflection of her tail to the side. An intromission occurs when the penis is inserted into the partner's vagina during the mounting sequence. The intromission is observationally recognized by a characteristic dismount; the male jumps back from the female at the conclusion of the intromission, and usually grooms his genital area. Mounts and intromissions are intermingled during ongoing sexual behavior, although mounts tend to be more frequent earlier in the behavioral sequence. An ejaculation completes a series of mounts and intomissions. The ejaculation behavior pattern is recognized when the male rises above the female's back with outspread forepaws. The male does not exhibit the dismount characteristic of intromission after vaginal insertion. Each higher level event in the behavioral hierarchy adds 6 Ia- nhv I. och hi. I- a!» On. 0 e a ‘v «Fe t... a‘. ‘ .5 7 c a .u. n . a \. .u» a I. are. e I h .n» a a z! N - I W. .. . rt . . {v u on be. element(s) to a lower level event. The ejaculation requires both elements of mounting and vaginal intromission. The intromission requires the elements of mounting and pelvic thrusting. Each behavioral event builds to the ejaculation, which terminates a sequence of behavioral events (see Figure 2.1). The frequency measures are the average number of behavioral events occurring prior to ejaculation. The mount frequency (MP) is the average number of mounts prior to ejaculation for a group of males. Similarly, the intromission frequency (IF) is the average number of intromissions over the same period. The ejaculation frequency (EF) is the average number of ejaculations for a group of males over the entire period of testing. The latency measures are defined by the occurrence of the behavioral events within a time continuum. Latencies are usually expressed to the nearest second. The first latency measure encountered in the temporal sequence is the mount latency (ML), the time from the introduction of the female at the beginning of the sexual behavior test to the occurrence of the first mount. Similarly, the intromission latency (IL) is the time from female introduction to the first intromission (Figure 2.1). The ejaculatory latency (EL) immediately follows the intro- mission latency. The EL measures the time from the first intro- mission of an ejaculatory series of mounts and intromissions to the ejaculation. The ejaculatory latency can be divided into intervals between intromissions, and these intervals can be individually measured and averaged to produce the inter-intromission interval (III) measure. An analogous measure to the III is the l‘l‘. .IIQII'II‘I I'- -fivd eu-u u -=.Jr~.w - ~ I -~.eez mmm3wm mOH>m menace mo masonw on» HH< .chHeanHpmHo radon m>am one he mo mmmnasmeHcmms oer modemspmsosov moamowopmo noamaooo pcommsmms mnoama>au one .mosmoam«:Mam Hooseusroem coesoaom res: phenom Seem o\m been no nooseoflsrua cardamom sunbeam rm enamel coapmswamoa maasmxa IIIIIHIHI 0.0 “no in. *- *- mc- m.o m:- wc- *1 Odemm m:- . m:- m6 we. we. m\ m:.. m was we. . o H w:- I WC. 0 ma mc- mcl H H m:- *. N.H oavmm mmem>< one Mom omesmm< poommm oz carom owmnm>< mapmcoavmmsd one Mom 6055mm< pommmm Hsmmcaammz < T32 0218 28 statistically significant, the average ratio is assumed meaningful and the average is incorporated. When only one study ratio is available for a particular treatment, the statistical significance is followed. The significant ratio from the one study is incorporated as generated from the reported data. Otherwise, the nonsignificant ratio (r-l.0) is incorporated in the model. On rare occasions when a single study ratio is nonsignificant, but due to its large deviation from 1.0 and/or a small number of experimental or control males, the ratio is incorporated as is, since the change from controls is potentially meaningful. The guidelines mentioned have referred to one point-ratio and averages of point-ratios, where one point is calculated per study. However, often articles report more than one experiment, providing more than one calculated ratio for each article and experimental treatment. If some doubt still persists concerning the reliability of the one point-ratio per study average, the average of all possible ratios is calculated. If the two overall averages closely agree, the one ratio per study average is incorporated. If the multiple ratio per study average is closer to the null ratio, it is chosen. However, if doubt continues, the mean of the multiple and single ratio per study average is incorporated in the model. All decisions cannot be defined strictly, as indicated by the above guidelines (Figure 3.1). A gray area exists between a meaningful and an inconsequential average ratio, lending the modeler some discretion. The modeler's judgement is aided to a degree by close association with the variability and the limits to that . upv: . '..- s:-: o.‘ a... fin gnu (.3 D 'I H- 9 o. I“: 29 variability inherent in each behavioral or hormonal measure and between different experimental treatments. 3.3 Equation Procedures When published studies provide multiple points for each treat- ment variable, a simple average of the study effects is insufficient. Usually a pattern emerges over the variable's continuum. For most behaviors and particularly for sexual behavior, the continuum is a time variable, such as repeated tests or days of treatment. The pattern can be expressed most concisely by a mathematical expression, an equation. The equation is derived by adjusting a standard equation form to fit the reported data. The shape of the standard form is chosen based on a graphic plot of the data from a single study or the average of multiple studies. The entire process includes the choice of standard equation forms, the preparation of the available data into one pattern, and the fitting of the standard equation form to the composite data. A choice of equation forms is given in Appendix B. Approximately fifteen general forms are given. The functions include a straight line, square roots, logarithms, exponentials, functions of "e”, and sigmoid forms. Most behavioral data could be effectively approxi- mated by variations of a sigmoid curve. However, many patterns of behavioral response do not closely fit the standard sigmoid curve, which has the same rate of change on either side of its midpoint. The behavioral response often shows an initial rapid change that then slowly tapers off to a plateau level. Due to the pattern (curve) p 0';- a... :22 .9” 5i In Us 30 frequent asymmetry, functions of "e" often fit the data better than the sigmoid curve. Therefore, the majority of model equations take an "e" function form.- Before the equation choice is made, however, the reported data must be organized and condensed. The Preparation of Data for Equation Fit As the control levels of behavioral or hormonal measures varied from study to study, the experimental/control (E/C) group ratio was calculated for each value of the treatment variable for each study under consideration. This produced a number of data point-ratios along the range of the variable's continuum. However, when no control group value was provided, ratios were calculated based on an average value of all data reported within the study. This was particularly the case for intrinsic variables; such as age (A), strain (ST), time of testing (TDN), time of year (YMON), and light cycle (LTPER). In addition, when too few points were available to obtain a meaningful average, the control value was assumed to be the control value reported by the model for the conditions of the particular experiment, or the control value was the average of control groups from articles originating from the same laboratory using the same strain. The selection of the appropriate standard equation form was made by visual inspection of a graphic plot of the ratio data. The more obvious tendencies in the data helped to eliminate most of the standard curve forms. Whether the data pattern increased or decreased over increasing values of the treatment variable, or 31 whether the curve accelerated, decelerated, or was linear was easily Spotted when compared with plots of the standard curves. The standard curve(s) most closely following the data pattern were then used for the calculation of fit. Data Averaging and Adjustment When more than one study reported three or more data points over the range of the treatment variable (three points are necessary to define a curve), an average curve was sought. An average E/C ratio was generated for each value of the treatment variable reported among all studies. If no value was reported in one study that was in another, an estimated value was calculated. To estimate a value, a ratio value above and below the missing treatment value was required. The estimated value was established by a linear approximation. In essence, a line was drawn between the two reported values adjacent to the missing one, and the missing value was found at the intersection of the line and the experimental treatment value. For example, in Table 3.1, study number 1 had no treatment ratio values for 7, 21, 35, 49, 56 and 63 days after castration (CAST). These values were estimated (in parentheses). The estimated values between 42 and 70 days post-castration fell on a straight'line between r - 0.994 and r - 2.524, respectively. The estimates were found based on the line: r - .05464(CAST-42.) + 0.994. The combination of estimates and actual values provided an equal weighting for the average ratio for each value of the treatment variable reported. The series of average ratios provided a single Table 3.1 A Sample Calculation of a Multiple Study Average for the Effect of Castration on the PEI Ratio. Individual Study Dataa b Adj. d CAST 1 2 3 . 4 Mean. Mean 7 (1.070)c 1.46 1.007 (1.071) 1.152 - 14 1.139 1.50 1.143 (1.217) 1.250 - 21 (1.072) 1.58 1.086 1.300 1.260 - 28 1.004 1.76 1.214 2.087 1.516 - 35 (0.999) 1.82 1.100 1.766 1.421 - 42 0.994 1.186 1.090 1.476 49 (1.376 1.479 1.428 1.934 56 (1.759) 1.564 1.662 2.250 63 (2.142) 1.436 1.789 2.422 70 2.524 1.971 2.248 3.043 a The studies included: 1 Whalen and Luttge, 1971 - SD (205) 2 Parrott, 1975 - SD (160 3 Davidson, 1966 - LE (58 4 Vomachka, 1976 - LE 198) CAST is the number of days postcastration. c All parentheses mark data points calculated by linear extrap- olation from reported data points. The final equation fit to the adjusted mean was: PEIr = 1.O*e-O.Ol565*CAST b d gaze EX'JE L: _. “~35C I~‘ s... ‘ J; t‘. A“ 33 pattern (curve) to be used for equation fitting. On occasion, adjustments to the average set of points were necessary when the ranges of the treatment variable did not closely overlap among the reporting studies. Separate values could not be estimated outside the reported variable's range. Therefore, when fewer and fewer studies provided values, due to the approach to the extremes of the variables range, the average curve would become more biased. To counter the bias, the average values of the studies with the wider range were adjusted according to the relative contribution of the studies of larger range. An adjustment was made when at least one study range was exceeded on the basis of the contribution of the other studies when all the studies were within each other's treatment range. The adjustment was the average of all study values divided by the average of the values from the studies with the larger treatment variable range. adj. r a Total x(n-l)/§» for pts with values at "n". (n-l) This compensatory £2232."33 calculated at the last treatment value before the range of any study was exceeded and then multiplied by the average value just outside the range of the overpassed study. For example, the range of study 2 and 4 in Table 3.1 was exceeded beyond 35 days post-castration. The compensatory ratio used to produce the adjusted mean ratio at point ”n" (CAST-42) in the series of treatment values (CAST) was the total mean at the ”n-l" value (i.e., at CAST-35, r-l.421) divided by the mean of the values for studies with reported values at ”n”, i.e., ratios for studies 1 and 3. The mean for studies 1 and 3 was (0.999 + 1.100)]2 - 1.0495. Ian. ”J . 3.. . :.:, A... . 1:2: 34 Therefore, the compensatory ratio was 1.354 (i.e., 1.421/1.0495). The compensatory ratio was then multiplied by the average for values at CAST'42 (r-l.090) to produce the adjusted mean of 1.476. If the study ranges were exceeded in a staggered fashion, the adjustment process would have been repeated each time the range of a study was surpassed. This adjustment procedure maintained the pattern established initially by all studies. It maintained the proportional relations among studies after values for some studies were no longer available. The termination of the treatment series may have been due to the defined limits of the experiment, the lack of inclusion of all treatment levels in the publication, or the cessation of behavioral performance. Accommodation of a Standard Equation to the Condensed Data After reported data was condensed into one set of values (data points) over the range of the treatment variable, the points - whether from a single study, an average of studies, or an adjusted average - could be fit to an appropriate standard equation form. The standard equation was fitted to the data points by generating an equation coefficient for each data point (value of the treatment variable). For example in the following equation, the a coefficient was -a(x-z) r = A(l - e ) + b sought. The values of r , usually the BIG ratios, and "x", the 35 value for the treatment variable, were known. In graphic form the "r and ”x” values corresponded to the ordinate and abscissa values. In Table 3.2, the value of "r” was the ratio of the number of males responding with intromission to the total number of males (PI) and the value of "x” was the number of days of injection with 1000 ug of testosterone propionate (DYTTP). The value of the coefficient, ”a", was solved. A reasonable fit to the data points was assumed when the sequence of ”a” values from low to high values of the treatment variable fluctuated randomly around the average of all ”a" values. In Table 3.2, the "a” values given in a column - one for each value of the PI and DYTTP - were expected to demonstrate no pattern. The ”a” values at low DYTTP values should not have deviated noticeably from the average ”a”s at high or middle values of DYTTP. The column with z-O showed an increasing pattern, while the column with z-l.5 showed no consistent pattern, and the "a" values fluctuated around' the average a - 0.1032. The desired fit was sought by a method of logical approximation. The sequence of "a" values were manipulated by changing other coefficients or constants in the equation in a desired direction based on the pattern of change in the ”a” column until an acceptable fit was obtained. It was a method of approximation, not an exact statistical fit. In highly variable systems, a tight statistical fit (curvilinear regression) would frequently produce an equation of greater complexity than would have been warranted to describe the relationship between behavioral (or hormonal) and treatment vari- ables. The state of understanding of behavioral systems has not 36 Table 3.2 An Example of the Fit of a Standard Equation to Composite Data The standard equation form, r = A(1 - -a(x-z)) + b, was * utilized for the fit to data for the effect of the repeated injection of 1000 ug TP/day as an adult, after castration at 30 days of age, on the PI. The specific variables were: x_= DYTTP - the number of days of continuous injection with TP and £’= PI - the ratio of males showing intromission to the total number of males. b = 0.0. calculated for each value of x, The preset equation coefficients included A_= 1.0 and The §_value was manipulated and the g exponent was ¥ z=0.0 z=l.0 z=2.0 z=l.5 DYTTP PI a a a a 3 .143 .0513 .0770 .1540 .1027 6 .286 .0560 .0672 .0840 .0747 9 .429 .0622 .0700 .0800 .0747** 12 .714 .1041 .1136 .1250 .1190 15 .786 .1028 .1101 .1186 .1142 18 .857 .1080 .1144 .1216 .1179 21 .929 .1259 .1322 .1392 .1356H 24 .857 .0811 .0846 .0885 .0865 27 .929 .0979 .1017 .1058 .1037 30 1.000 - — - - Average .0877 .0968 .1130 .1032+ *- The data were taken from deersten, 1975 (177) (N=14 males). ** The values designated as outliers. + The chosen equation value for §_was 0.103, when A;1.0, b=0.0, and z=l.5 . 37 yet grown to the extent that complex relationships would be expected between variables. In Table 3.2, the coefficient available for manipulation was ”A" and the available constants were ”b" and "z". The values of ”A” and "b" were set by the nature of the PI, which ranges between 0 and l. The maximum PI would be all males responding and the minimum would be no males responding. ”A” was the amplitude of the equation, the range of the BIG PI ratios, and the ”b” the minimum value. In Table 3.2, ”A” equals 1.0, because the highest and lowest ”r” ratio values were 1.0 and 0.0, respectively. The value of "b” was zero. Therefore, "2" was the remaining candidate. The ”z" designated the point on the abscissa (DYTTP value) where the curve started, or the equation equaled zero. The "2” shifted the curve to the right along the "x" axis when ”2” was increased. In the example, the direction of manipulation was based on the Sequence of ”a" values. With "A” and ”b" foreordained, the value of '"2" was initially set at zero (see first “a" column). ‘When z-O, "a" tended to increase over increasing values of DY'I'TP, a condition of Poor fit. Because increasing the value of "2" would result in a Ilarger change in "a” at low values of ”x” (DYTTP) than at its higher ‘Values, "z” was increased to 1.0 to reduce the increasing ”a” Pattern. As z-l did not eliminate the ”a” pattern, "2" was further increased to 2.0. This made the DYTTP-3, ”a" value a little too high 80 z-l.5 was tried. The z=l.5 manipulation provided a sequence of ”a"s With a reasonable fluctuation about the average a-O.1032. Therefore, the model value for ”a" for the PI-DYTTP equation was a-0.103. Sometimes, the values of "a" would show large fluctuations, so up. '5‘- ... a e e P. 5': uh «I. it c . 4 P. u a . . o n.— .. a a: .0 a .14 .6 a 3» AIM n e not .fl- .4. .i. . e a 6 Au .3 .n .. his a - #0 wk Ala E An: .vl 38 the assessment of a reasonable fit became more difficult. The selection of certain a values was utilized when large fluctuations occurred. The most deviant a values were removed from the sequence of ”a"s, as a noticeable outlier would bias the average "a" inordinately. The selection of the values to expurgate was based on the original graphic plot of the condensed data. If an ”r" value was a noticeable outlier, i.e., off the visual pattern of plotted points, it was dis- counted. Similarly, points on the less significant portions of a curve - regions where changes in the coefficient had a lesser effect on the equation values - were sometimes discounted. In the case of a sigmoid curve, points at either tail of the curve has coefficients which have less effect with greater fluctuation and less effect on the shape of the curve than points near the midpoint of the curve, which more tightly define the rate of change controlled by the coefficient. When the mean of all "a" values was closely matched by the mean <>f the selected "a" values, the mean with the outliers removed, a reasonable fit was assured. Where the total and selected means did llot match well, the selected mean was incorporated in the model iaquation. If a question existed concerning the representative nature <>f the selected "a” values, or if the number of selected points was 'Very few (less than 4), an average of the total and selected means Was incorporated as a compromise. The fit for the data in Table 3.2 can be seen in Figure 3.2 in graphic form. As stated before, the best fit for "a", the equation exponent, was 0.103, when z-1.5. Although no strong outliers were present in this example, a test of total and selected "a" means could be demonstrated. The more noticeable outliers were the values If. A 39 1.01 o 0-9-1 008- 0.74 0.61 0.5- 0.4- 0.3- Alternate Curves O—GPI data plot ——Best fit - a=0.103, z=l.5 0'21 "-'°"-Fit # 1 - a=0.088, z=0.0 :7 -—_mn#3 -$mn;zafi 0.1— f I I I I 0")" ' I ' I f r l 1 I l o 3 E 5’ 12 15 18 21 24 27 3o DY'I'I'P Figure 3.2 Different Fits of Sample Data to a Standard Equation Form. The sample was the relationship of PI data to the DYTTP (days with TP) variable as given in Table 3.2. (* - marks the points designated as the outliers) 40 at DYTTP - 9 & 21; they were also the highest and lowest values for "a" (Table 3.2). When those two points were eliminated to generate the selected mean, the average became a-0.1027. Because the agreement of the total and selected means was so close, a-0.103 was undoubtedly a proper fit for these data. When no sequence of "a" values was acceptable, another coeffi- cient or constant in the equation was manipulated. In the equation, -a(x-z) r a A'e + b "A" and "b" were alternates to "2" under some conditions. The manipulation of the "a" sequence with changes in "A" and "b" was frequently useful when the E/C ratios ranged potentially from one to zero. For example, the relationship of the weak androgen, éindrostenedione, to the ratio of males responding with ejaculation (PE) during a postcastration recovery regime could potentially range from zero to one, but actually the PE rarely grew larger than 0.50. 133a constant, "b", would again be zero, as the minimum ratio would be zero. The sequence of "a" values over the days of androstenedione 1Iljection would have been recalculated. If some pattern was observed 143 the "a" sequence, the value of "A” could be shifted up or down until the "a" sequence had no consistent pattern. On occasion, more than one standard equation form was a 'Pomential candidate for the data fit. If so, each alternative equation form was used, solving each for the apprOpriate coefficient, Which was usually designated "a". After solving for the "best a" in each case, the fluctuations of the "a" values about the a 63’671 . a Do .1 . ez;e: '; 2. a .... .- . 5.. ‘- " ..; \ '. in , one 3 . 0‘.“ fl :5 .. 41 average for each equation were compared. The set of "a" values with the least evident deviation from its average determined the equation form to be incorporated in the model. In summary, the shape of a relationship between a dependent behavioral or hormonal variable (E/C-r) and an independent experimental variable was established graphically. The shape of the relationship determined the standard equation form to be adjusted to the composite data. The Opportune coefficient was solved for, with or without the manipulation of other coefficients or constants within the standard. Some of the coefficients and constants were preset by the nature of the variables. When no discernible pattern was observed over the range of the coefficient values appropriate to each experimental average data point, the average coefficient value or some adjustment thereof was considered a reasonable fit. The 'alternative indication of a reasonable fit was a random fluctuation <>f coefficient values about its average over the entire sequence of "ar values. The procedure could be extended to more than one Ertandard equation form, which then required a comparison to establish the equation with the minimal variation about the fit. 3.4 Straight Linear Approximations The straight line was the best Option when too few data points ‘Were available to discern any consistent relationship, the variance among points was too high to discern a pattern, or a cluster of many points had no definite curvilinear pattern. With very few data points along the range of an experimental variable, a statistical fit 2833 ‘EAA 3.x... '0“ "1 "s ...e .DOin 621a 42 was no more meaningful than a graphic or visual fit. At times the statistical fit was less meaningful. Sometimes a predictive line was more meaningful when anchored to an expected point or a theoretical point. For example, if a behavior was initially at a zero level prior to the initiation of treatment, the line was best anchored at zero at the zero value of the treatment variable rather than some value greater or less than zero established by a statistical fit of the available data (Figure 3.3). A straight line was also useful in bridging a region of the range of a treatment variable where no data were available. The straight line was the simplest connector between any two known points or regions. Implicit in the use of a line was the assumption of no particular pattern within an ”empty” area. The procedure for fitting a line to the data was similar to that :for the equation-curve. The line was determined from the pattern of the available data and its relation to other data or theoretical tubints. The graphically represented line could be drawn to connect an anchoring point and a data point, two data points, two average POints generated from three points, or to follow the direction of 8everal points, with or without consideration of a theoretical trend (see Figure 3.3). The equation for the line could then be Calculated. The equation for a straight line, y - a°x + b, required the Calculation of two values; ”a", the slope, and "b”, the y-intercept. As each point was defined by two coordinates, (xn,yn), and any two points (x1,y1 & x2,y2) could be used to define the line, the slope was the difference between the two ”y" coordinates divided by [R v . '2“, Ratio 43 a Multiple Points 1.0 0.8 - \ \ 0 0.6- \ 0.4-1 \ 0.2 "‘ . \ N Three Point Fit 0.0 E/C 1.0 0.8 . 0.6 . 0.44 0.2 -i 0.0 C Theoretical Anchor Assumed 0'0 III I 012 34 5 67 8910 T I I l I 1 Treatment Variable Figure 3.3 Linear Approximations to Three Different Types of Data Poir)it Distributions. (--—--Model Approximation; — - —Stetistioa1 Fit . 0.. ...a A... t.u3 -.\‘ 44 the difference between the two x coordinates. slope (a) - (Yz‘Y1)/(x2_xl) Establishing the y-intercept was not as clear. The value of y (the E/C ratio) when ”x" (treatment value) equalled zero could be read from the graph or calculated if the slope and one point was known. The intercept was usually not found by an exact statistical fit. The intercept, as well as the slape, were often limited by considerations pertaining to the relationship (Figure 3.3a). Aspects of that relationship included an initial control level of 1.0 or 0.0 and relations to data at another part of the variable's range. Once a graphic line was drawn to relate three or more points, the deviations of each point from the line were found. The (deviations were grouped according to those either above or below the line. The sums of the above and below groups were compared. If the Sums were not equal, the value of the y-intercept was raised or lowered, keeping the same slope, until the sums of the two groups ‘Were approximately equal. When several lines were possible, the line ‘Vith the lowest Least Square value was placed in the model. ’ Again, the purpose of these procedures was to find a fit repre- EBentative of the pattern of response demonstrated in the available literature rather than an exact fit to the particular data points. 'This approach reduced the possibility of required changes in the Model equations due to the addition of data from each new study, Changes that would be required each time if the fit were statistical; a more representative line would tend to be consistent with present 5"" in“ IP' ‘0 ..t.;‘ e 45 and future data. For a high variance system, as sexual behavior is, an exact measurement would provide great precision, but if the addition of each new point required a recalculation of the numerical relation- ship, the tool would have been too fine for the object measured; the height of an elephant is not measured with calipers. h... Chapter 4 Model Structure and Preparation 4.1 The Basic Structure of the Model The model is composed of fourteen separate units. The basic structure is a backbone, the main program, controlling the operation of the other subprograms, which relates the subprograms calculating behavioral or hormonal output values (eleven in number) and the diagnostic subprogram, which provides a reliability value for the output (see Figure 4.1). The Main program controls access to all Operations. It presets all the input variables, calls the Input subprogram to reset user designated treatment or increment variables, increments all variables for each successive iteration, controls access to the calculation subprograms, and finally calls the diagnostic subprogram. After all treatment and increment variables are preset at the start of the main program, the Input subprogram is called to read in the values for any treatment or increment variable the user wishes to reset. The Main program proceeds to call the calculating subprograms, generating the Output values. Communication among the Main and subprograms is through COMMON memory storage. After the output of the behavioral and hormonal measure values and the reliability values generated by the Diagnostic subprogram, control returns to the beginning of the Main program for incrementation of the input values. The iteration subroutine, when accessed by the Main program, 46 4? MAIN PROGRAM SUBPROGRAMS Preset Variables Input Read & Reset Subprogram Variables Iteration Increment Subroutine Variables Define Hormonal Variables —---------—-_._d L #4 Define of Penile Spines I Penile _ s A _____ Vf ?f?fi____-o{ Penis Wgt. J Define Behavior Variables H DIAGNOSTIC Output Variables I m - PI PM Calculate Diagnostic Ranks Figure 4.1 The Basic Structure of the Model 48 increments all input variables with each cycle of the model. Each treatment variable is added to its associated increment variable to reset the treatment variable values for the current cycle of the model. For example, if a male rat's age was set at 200 days by the user and its increment set at 7 days, the first set of output values printed would be for a male of 200 days of age, the second cycle for a male of 207 days of age, out to the fourth cycle at 221 days of age. This number of cycles would be set by the NINC value of 3, the number of iterations. The same process holds for any number of input variables. The Main program controls the order of access to the hormonal, behavioral, and penile subprograms, and it accepts the output values from those subprograms, storing them for future output in arrays. When all output values are calculated, the program prints 3 display of the output using a display subroutine. The last activity in a cycle is calling the Diagnostic subprogram, which calculates and outputs reliability values for all output measures. The calculation subprograms are in the greatest number. Each of these subprograms independently generates its output values, whether behavioral, hormonal, or penile in nature. The only way an output value from one of the subprograms can influence another is through the Main program. The hormonal subprograms generate a normal resting level and an experimental plasma hormone value. The testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) units generate their appropriate plasma levels, based on the established treatment variables. The behavioral units generate a control and experimental value for each of the following behavioral 49 measures: ejaculation frequency (EF), intromission latency (IL), intromission frequency (IF), ejaculatory latency (EL), post- ejaculatory interval (PEI), and the ratio (percent) of males responding with ejaculation, intromission, and mounting (PE PI PM). Each behavioral measure has its own subprogram, with the exception of the ratio-responding measures which are combined into one large unit. Finally, the penile units are two in number. They provide normal and experimental values for the number of penile papillae in a cross section of the glans penis (PP) and for the weight of the whole penis (PW). The Diagnostic subprogram is a third type Of unit. It generates as estimated measure Of reliability for each output value, based on the values of the input, treatment variables. It is a repository Of the variation across the range Of all variables that are input and provides an independent reliability for each output variable through separate subprograms for each of the behavioral measures controlled by a single Operational unit. The printing of the values from this subprogram signals the end of the current iteration cycle. 4.2 Modeling Procedures The construction Of each model part, whether a separate subroutine or subprogram, involved developing each unit separately, so they Operate as semi-independent units. Each unit was constructed following a few general procedures. The description of the procedures does not require an explanation Of the FORTRAN language, which is beyond the scOpe of this paper. The procedures depend upon cau- res 50 the type of program or subprogram. The major types include the Main program and Input subprogram, the various behavioral and hormonal calculation subprograms, and the Diagnostic subprogram. Principles for the Main and Input Programs The Main program and the Input subprogram are the most complex. The Main program establishes an initial value for all input, treatment variables and incremental variables. These variables are listed and described in Appendix A. Initially the values for all variables are established using DATA statements, that set the values for each variable prior to any other activity of the program. After the variables have been preset, the individual using the program can reset them to define any experimental condition desired. The reset process is handled by the Input subprogram, the first subprogram accessed by the Main program. If the user designates no values, the program generates the output values for a normal adult control male group determined by the preset input variables. the reset process is accomplished through the NAME variable. The user is supplied with a list Of NAME designations (alphanumeric characters listed in Appendix A), one available for each input variable. When a value for NAME is designated, the user must follow with a chosen numeric value for the named input variable and its increment variable. This double input procedure may be repeated for as many input variables as desired. When the name variable is given the value of FLAG, the reset process is terminated and control returns to the Main program. .Afl. bvu- V2131 isa It?! a: 33m 51 The iteration subroutine is called from the Main program at the end Of the cycle. It increments each input variable by the value Of its associated increment variable. The Main program then continues from its beginning with the new set Of input variable values to recalculate the output variables. The cycling of the Main program continues until the number of iterations set by the NINC variable, the first value set by the user before any NAME variable, is attained. At that point the model ends and all execution is terminated. When all the values for the input variables are established - either by initial reset process or through the iteration reset process - the Main program proceeds to access the subprograms that calculate the behavioral, hormonal, and penile output variables. All of the 11 output subprograms are called, and the experimental and control output variable values are calculated and returned to the Main program. The values for the input and output variables are communicated through COMMON memory storage. The Main program controls the order the calculation subprograms are called. The first group called is the hormonal subprograms, which calculate the values for plasma T, In, and FSH. An injection dosage Of testosterone is calculated by the main program based on the plasma level Of T, which in turn was determined either by a user designated value (PLT) or through a cyclic feedback with the LH and FSH subprograms. As LH and FSH from the pituitary normally controls the production of T and its consequent level in the blood, their subprograms interact within the Main program until their values are internally consistent. The interaction is accomplished by converting v --" ‘1' ‘Uro 5...!” “'ru . 96:15 52 each plasma level value to an injection dosage, which then is an input variable when the hormone subprograms are recalled. The T subprogram is dependent on changes in the LH and FSH subprograms, and XEEENXEEEEf When consistent values among the three hormone subpro- programs are attained, the Main program proceeds. The second subprogram group is the penile units. The PP and PW subprograms require no special manipulation. They report one set of output variables, one for the penile papillae number and one for penis weight. The final and major group of subprograms called is the behavioral group. All the behavioral subprograms, except the EF, are embedded in a DO loop to cycle the remaining subprograms through five ejacula- tory series plus the consequent PEIs. Therefore, the IL, IF, EL, PEI, and PEPIPM subprograms are called five times in sequence, each time reporting control and experimental values for the apprOpriate number of the series. In addition, after calling all calculating subprograms, the Main program calculates ancillary measures Of sexual behavior and the BIG calculation subprograms. The first ancillary measure is the inter- copulatory interval (ICI), the average interval between intromissions in each ejaculatory series. It is the ejaculatory latency divided by the intromission frequency (EL/IF), calculated for the experimental and control values, independently. The 1013 are followed by the total response measures. The totals represent response averages that occur when both responding and nonresponding males are included together. The total behavior measures allow for comparisons with published data including zero data. As the IL, IF, EL, and PEI model bi '- TIe ': , :"9n ‘.I§ I 0". u..- are r ‘1 ‘no 31... . u q ba‘\2 OW‘N U‘,‘ l 53 values reflect only responding males, the model values are multiplied by the appropriate ratio Of males responding (i.e., PE or PI values). The values calculated are: TOTIL-IL*PI TOTIF'IF*PI TOTEL-EL*PE TOTPEI=PEI*PE Furthermore, the experimental/control (E/C) ratios are calculated from the two output values from each subprogram. Therefore, ratios are reported for plasma T, LH, and FSH; the EF, IL, IF, EL, PEI, PE, PI, and PM behavioral measures; and the penis weight (PW) and papillae number (PP). The Display subroutine is called following the completion of all calculations and the loading Of all output values in appropriate output arrays. The Diaplay subroutine causes the printing of the separate experimental and control values for the IL, IF, EL, PEI, PE, PI, and PM and the experimental value for the EF on one line. The five consecutive ejaculatory series follow on the next lines. The ancillary behavioral values are given next across the five series; they include the ICI values and the experimental total measures. These are followed by the E/C ratios for the behavioral measures. The hormone and penile experimental values then appear with the number of hormone cycles - the number of times the program needed to loop between the T and LH and FSH subprograms tO result in mutually agreeable values. (The last values displayed are the E/C ratios for the hormonal and penile measures. The entire display is repeated for each iteration of the program. The Main program now calls the Diagnostic subprogram, that M I“ ‘31 54 calculates and displays reliability values for each behavioral measure over all behavioral series. A more detailed description of the Diagnostic subprogram is given in a later section. When the number Of iterations reaches the value of NINC, the Main program terminates. Calculation Subprogram Procedures The eleven calculation subprograms include six behavioral units (EF,IL,IF,EL,PEI,PEPIPM), three plasma hormone units (T,LH,FSH), and two penile units (PP,PW). Each of the subprograms is separated into divisions. The multiplication of all experimental effect ratios within each division produces an overall ratio for that division. The multiple of all the divisions produces the experimental output value for the particular subprogram. The control output value is the resulting ratio from the first division, that calculates a value for the effects appropriate to a normal untreated male rat. The number of divisions is potentially seven. The divisions are for control male (intrinsic) values, experimental and stimulus manipulations, sensory treatments, major gonadal hormone treatments, androgen effects, nongonadal hormone treatments, and drug effects. However, all divisions are not always present in every subprogram. Divisions are combined if few values are calculated for one division, due to a lack of available data or the lack of any experimental effect (i.e., the E/C ratio is 1.0 for a given treatment). Frequent- ly the hormone treatment division is combined with the androgen and/or drug or nongonadal divisions. . [:01‘ ‘65.! ”fl“. ‘9 0". Vav4. A“ 2dr: 55 The first division, the control measures, contains all the variables required to define a normal male left untreated. The variables include the strain, age, month of the year, light cycle, and time of day. These variables are handled somewhat differently, because the control variables have no actual E/C ratios. They use ratios of the particular condition to the average or normal adult condition. For example, the responsiveness Of the male changes during the dark period, so a TDN value on either side Of 5 hours, the approximate time Of most testing, into the dark period would be a ratio of the response at the particular TDN value to that at 5 hours. All variable ratios are in turn multiplied by the average response across all control groups for the subprogram measure. The experimental division is a less distinct collection Of variables. It contains variables that attempt to manipulate the males; behavior and conditions relevant to the testing situation. The test variables include the time between repeated tests (TBT), the males' prior sexual experience (a normal male is assumed to be completely experienced), and the caging situation. The behavioral manipulation variables include enforced ICI's and PEI's, the receptivity Of the female partner, female exchanges, electric shock, positive and negative conditioning paradigms, and other miscellaneous manipulations, such as testing males and females in groups or use of collars to prevent genital grooming. The gonadal hormone division contains castration, cryptorchid- ectomy, and injections Of testosterone or estrogen in various forms. The androgen division contains calculations for the remaining androgens. These include dihydrotestosterone (DMT), androsterone, - JAGV‘ .5- Va: 10: 56 androstenediol, androstenedione, androstanediol, androstanedione, and hydroxytestosterone in various forms. The following division is a miscellaneous nongonadal hormone treatment category, and it is usually attached to another division. It includes the surgical removal of the hypothalamus, adrenal glands, thyroid, or pineal gland. Furthermore, injections of LH and/or FSH, human chorionic gonadotropin (ECG), and forms of progesterone, prolactin, and pregnenolone are contained within. The final division holds anti-androgen and anti-estrogen drugs of various modes of action. Included are androgen mimics such as fluoxymesterone, anti-estrogens such as MER-ZS, anti-androgens such as cyproterone acetate (CYA) and flutamide (FL), and aromatase inhibitors such as aminoglutethimide (ACT). Also, effects of starvation are tacked on at the end. Information moves between the calculation subprograms and the Main program through shared COMMON memory. The output variables, an experimental and control value from each subprogram, are transferred through a separate COMMON block. Several general principles are in Operation in each of the calculation subprograms. The organization of the subprograms is essentially linear. The progression Of calculation moves from the beginning to the end of the subprogram, each division and each variable within the division, in sequence. Basically, no internal loops, no returns to earlier calculations, are present. Calculations for an input variable are skipped if the value of that variable has not been changed from its preset value, usually zero. For example, the equation for the number of males responding i: :: ales .He 1 5131! 5'11 '61: :re tre Se: Pr 57 in the PEPIPM subprogram to a dosage of testosterone is bypassed unless the value for the input variable, DTTP, is greater than zero. The unrequired equations and variable values are bypassed with IF statements. Limits are set for all calculations exceeding a theoretical value or exceed maximum or minimum values inherent in the averaged data. The limits are frequently required to prevent continuous extrapolations beyond the data supported variable ranges. For example, an equation for a straight line would generate solutions larger than 1.0 for some elements of the PEPIPM subprogram, and as more than 1002 (r-l.O) Of the males cannot respond, a maximum limit is necessary. The limits are established with IF statements also. Access to some treatment ratio values or equations is controlled with controller variables. These integer variables provide the user with a list Of different related experimental treatments, each treatment having a whole number designation (descriptions in Appendix A). For example, NFRESH is a controller variable with four possible treatments pertaining to when a female partner is switched during a sexual behavior test. If the switch was tO be made at each ejaculation, NFRESH would be set at one (1), and at ten (10) if the switch occurs only at sexual satiety. Logical IF statements serve to test for the value given the controller variable, and with the appropriate value allow access to the value or equation for the BIO ratio for the particular variable and output measure. After the various program instructions have been followed to produce a number of treatment ratios, these ratios within each division are multiplied together, producing a division ratio. The v.- .o‘ 6!: a”. .-. Sit-s H ex; fool I- U?“ Va fi an 88 th. Ca me; 58 division ratios are multiplied together to form the overall experimental output ratio. When the overall experimental ratio is multiplied by the control output variable, the value from the normal control division, the experimental output variable emerges. If only a male stimulus Object treatment (SEXSTIM-lO) is desired, the experimental division and overall experimental ratio for the IF subprogram would be 0.50. If the normal control variable value was CIF - 10.0, the experimental output variable would have been IF - 5.0 when the experimental ratio is multipled by the control value. 4.3 Diagnostic Preparation The diagnostic portion Of the model provides a measure of the relative reliability for the behavioral output. The reliability is expressed as a rank from 0 tO 10. Each rank is based on the amount of data and the variability within the data available. The rank values do change over the range Of each input variable and over the five consecutive ejaculatory series. The eight behavioral outputs (IL,IF,EL,PEI,EF,PE,PI,PM) are treated independently with regard to the generation Of ranks, so the ranks can vary from measure to measure for the same input variable. The average rank, minimal rank, and the midpoint between the two are reported as a second output section. The Diagnostic subprogram is called by the main program after the calculation Of the output variables. The Diagnostic subprogram calls the rank generating subprograms, one for each behavioral measure. Each reports one rank for each input variable designated by the a." «U. 5922 3n.- the Here 011pt Vafi the 59 the user to the calculation subroutines. The subroutines generate the average and minimal rank for all designated input variables. The Diagnostic subprogram displays and stores the final ranks as a matrix and reports the ranks, one for each output measure and each ejaculatory series, for each cycle Of the total model. Diagnostics are provided for the behavioral variables only. The hormonal (T,LH,FSH) and penile (papillae and weight) variables are not provided with reliability values as these variables hold a secondary position within the model. The plasma hormone and penile output measures provide information on the concurrent condition Of the hormonal system and penile structure, which only indirectly influence the generation Of the behavioral output. The behavioral responses are the primary focus of the model, so behavioral reliability measures are deemed sufficient. The following sections describe the exact procedures required to generate the diagnostic ranks and the general structure of the diagnostic programming. The measures of the data reliability used for the generation of the diagnostic ranks follow immediately. Calculation Of the Reliability Measures Six numerical measures provided the basis for the reliability of the behavioral response to the input variables. Reliability measures were developed for each input variable for each of the behavioral output variables. Three measures provided information about the variability within the available data and three measures described the amount of data available. all :I ' 7'. (iv. 60 The variability measures were statistical. The deviations of all reported data points from the model value were found. Several deviation values could occur over the range Of a single input variable. These deviations were found for all input variables for each behavioral output measure. For example, the relationship of the input variable, CAST (the number of days after castration), to the output variable, EL (ejaculation latency (sec.)), was supported by 15 data points from three studies (59,198,205)(see Figure 4.2). The difference between each data point and the corresponding model value provided a deviation value for each data point at the appropriate value of CAST. At CAST - 56 days the model value was based on the equation: CASEL =- .021(CAST) + .774 8 .021(56) + .774 = 1.95 As the actual data point was 1.537 (E/C ratio), the deviation value was the difference, 1.537 - 1.95, of -.413. The remaining 14 points were generated the same way. The statistical measures of variability about the model value(s) made use of the deviation values. The statistical measures were combinations of the mean, median and standard error. The sum of the mean and the standard error (§'+ SE) gave an indication of the degree of variation surrounding the model value(s). The second measure, the ratio of the standard error to the mean (SE/i), showed the relative contribution of the SE to the first measure. This ratio required an adjustment to the more limited range Of 0.5 to 1.0, because otherwise it has an excessive influence when combined with the other deviation measures. The choice of 0.5 61 3-5 ' 0) :kAA fl H 1| 3.0 I! || A Long-Evans strain : ‘ [3 SpragueéDawley strain 1' “ —Model line 2.5 i a (n)Number of males responding .' l EL I ' 1 l 1 | 2.0 : ‘ 1 I (2) Deviation ratio : ‘ A _ Value 1.5 I 9 A a ' (4) <7) .' <1) “ '(7) (2) a “ n 1.0 (6) , (3) A (e), " n é§\\§aflrfig) 0.5 (5)(4) 0.0 o 14 28 42 56 7o CAST (days postcastration) Figure 4.2 The Relationship of Data Points from Three Studies to the Model Values Utilized in the Calculation of Deviation Values. The values are for the relationship of the CAST to the EL ratio variables. (* designates the point not used in the deviation calculations because it was an extreme outlier, representing the response of one male rat.) “A H‘a ii He 62 as the lower limit was arbitrary. The second measure was generated in the following manner: st =- o.s (SE/3E) + 0.5 The third statistical measure was the ratio of the median to the mean (MDN/X). The ratio represented the degree of divergence of the particular set of deviation values from a normal distribution. The greater the divergence from a normal distribution was, the less reliable all the statistical measures were. The MDN/i ratio was adjusted so the measure ranges only above the 1.0 ratio for the normal distribution, so the overall reliability is altered in one direction only from the minimum absolute fit. The third measure followed the form: Mr - [MON/'22 - 1.o| + 1.0 The three measures of data quantity were the total number of points (Np), the total number of studies providing those data points (N8), and a weighting for the number and type of male rat strain (STw). The strain weighting was calculated using: STw ' Z (Nst)2/sttudy (where Nst was the number of studies utilizing the same strain and Nstudy was the total number of studies involved) Both the measure for the number of points (Np) and studies (Na) required alteration. A factor that increased with decreasing number of points or studies, i.e., decreasing reliability, was needed. Three studies or three points were chosen as the cut-off value 63 for decisions concerning the weighting of the study or point factors. One or two studies were frequently inadequate in providing distributions of points for the statistical measures of deviation. The low number of studies tended to underestimate the behavioral variation, because the amount of deviation from the model was based on the methods used to generate the model values or equations. With one or two studies, especially studies from the same laboratory, a closer fit could be provided than if a number Of studies were involved. Three data points were chosen because three points were required to indicate whether the relationship was linear or curvie linear. In general, a closer equation fit can be made to a small number of points than to a large number for a variable phenomenon. This had to be adjusted when considering the reliability. When all deviation measures were viewed and compared, a simple difference factor like (4 - N) was found to be inadequate. Some reasonable measure of reliability needed to be established to counteract the fitting procedure. The requirement that the ranges of the statistical measures of deviation for a single point and/or study not overlap the ranges of the statistical measures for three or more studies and/or points was deemed reasonable. To accommodate this requirement, the factor for studies was established as: a _ 2 Nr (4 Ns) for Ns.$ 3 For the factor for number of points, which was considered in low numbers as a stronger measure of unreliability than study number, the difference needed to be doubled and squared to meet the requirement: If h! L! “J 64 ))2 for N < 3 up . (2(3 - N points points If the reliability factors for points and studies are combined, the following factor table results: Table 4.1 Factors For the Total Number of Studies and Points Npoints l 2 3 l 144 36 9 Nstudy 2 l6 4 3 l The table effectively counteracted the biases in deviation values induced by the calculation of model equations of values from a small number of points and studies. For example, two points can be fit exactly, i.e., zero deviation, but the resulting reliability measures are not representative of the pOpulation of male rats. When all six measures of reliability were adjusted so they related as multiple factors, providing a single, combined numerical reliability measure (RN). The factors of the combined mean and standard error, Mr, and NF were stronger factors. Table 4.2 provides a specific case demonstration of the calculation of the six measures and the resultant NR. When a larger data base was available for a particular variable, 65 Table 4.2 * A Sample Calculation of the Numerical Reliability Value (NR) From the Six Measures of Reliability. 1) i + SE = 0.331 + 0.06235 = 0.39335 2) St = (SE/f)*0.50 + 0.50 = (0.06235/O.331)*O.50 + 0.50 = 0.594 3) Mr =|Mdn/f<' - 1|+ 1.0 = |0.510/0.331 - 1| + 1.0 = 1.5415 2(N )2 2 2 2 4) STW= st /N2 =(2+1)/3=5/9=0-556 study 5) Nr=(4-N >2=(4-3)2=1.0 study - 2 .. _ 6) NP — (2*(3 - N )) for Npts<3 ; with Npts - 15, Np —1.0 pts § ' * * * * * (X+SE) Sr Mr STw Nr NP 0.39335*0.59¢*1.5415*0.556*1.0*1.0 = 0.2003 *- The example presented is the relationship Of the CAST input variable to the EL ratio output variable. 66 divisions were made within the variable's range. Reliability measures were found within each division and the NR calculated. The division allowed changes in the NR over the range of an input vari- able. The CAST input variable in the PE (ratio of ejaculating males) output variable provides an example of a variable with divisions. The CAST - PE relationship was divided into 18 parts, each with an average number of points of 6 (total N a 109). The pattern of the deviation means followed a linear relation represented by: SEPE - -.002594 (CAST) + .234, 0 _<_ in: _<_ .205 The standard errors showed no discernible pattern over the range CAST, so the average deviation SE was adopted (SE - .03394). The NR was calculated for the maximal and minimal i and SE segment for any divided input variable. The maximum and minimum values for the CAST - PE case were respectively 2'- .205 and .0135 for the segments CAST - 3-5 and 70-85 days. Because the deviation equations did not fully represent the fluctuation about the equation line, secondary deviations of the segment means or SEs from the deviation line were added. The secondary deviations were generated in the same manner as the primary point deviations. The secondary deviations were added to the primary deviations taken from the deviation line. Tot. (i + SE) - (ail +AT2) + (A3131 +ASE2) For the CAST - PE example, the maximum and minimwm extremes were as follows: 67 Tot.max I (.205 + .0707) + (.0339 + .0163) = .3259 “rot.min - (.0135 + .0707) + (.0339 + .0163) =- .1344 The remaining five reliability measures were assumed constant over the range of the input variable supported by data. The changes in the RN were, therefore, a reflection of the changes in the deviation mean and SE sum. The segmentation procedure made the variation along the variable's range more comparable with variations for input variables having no ranges such as all the sensory variables and most of the experimental nonhormonal variables. Generation of the Ranks After the numerical reliability values were developed for all the input variables for each of the eight behavioral output variables, the RNs had to be converted to ranks to aid user intelligibility and the comparison among output variables. The conversion to reliability ranks occurred in two stages. During the first stage, the ranks were generated from the RN values and set to range from 0.1 to 9.7. The curtailed range was necessary to separate the deviation values demonstrating variability from those that did not. The zero rank was reserved for input variables with no data or outside the range of the values of an input variable. The 10.0 rank was reserved for deviation values that were all equal over a particular range of the input variable in multiple studies. In almost all cases, the equal deviation values were zero. 68 These consistent zeros occurred primarily during the early stages Of a recovery regime under hormone replacement, where males had stopped responding sexually prior to the start of treatment. The ranks were established such that a high level of reliabil- ity, i.e., little deviation from the model values, was represented by the higher ranks and the low levels of reliability were represented by the low ranks. The reciprocal of the numerical reliability value (NR) was the core of the rank generation. As the reciprocals (l/NR) ranged from almost zero to approxi- mately one hundred and the ranks were set to range from 0 to 10, the square root of the reciprocal was taken. The adjustment for ranks ranging from 0.1 to 9.7 resulted in the following equation: R = 0.96 l/NR + 0.10 In the second stage the initial ranks (R) were realigned because the initial distribution Of the R values was primarily at lower values. Ranks showing a greater degree of discrimination was desired To spread the clump of low ranks, a division was chosen at those rank. supported by data from three or more studies for the same reasons mentioned before. All the ranks could then be prOportionately adjusted. The median rank of 5.0 was set at the approximate bottom Of the three study supported range. The approximate average R of the division point for all behavioral variables was R - 1.7 (range: 0.78 - 2.25). Therefore, the initial Rs of 2.0 to 10.0 were contracted to a rank dispersion of 5.0, ranging from 5.0 to 10.0, and the initial ranks of 0.1 to 2.0 were expanded to 5.0 rank dispersion, ranging 69 Table 4.3 *- A Sample Calculation of a Reliability Rank from the Numerical Measure of Reliability (NR). NR = 0.2003 RI = 0.96,/ l/NR + 0.10 = 0.96./ 1/0.2003 + 0.10 = 4.894 RF = 5(RI - 2)/8 + 5 = 6.808 (use of the equation for RI:>2.0) Final rank value reported as 6.8 * . The sample data were for the relationship of the input variable, CAST, to the output variable, the EL ratio. 70 from 0.10 to 5.0. The proportional shift of R values was accomplished with the following formula to provide the final model ranks (RF): I a) for 10.0_>_R_>_2.0, RF - 5(R - 2)/8 + 5 or RF 9 2.4758 l/NR + 0.1 An example of the entire procedure is given in Table 4.3. By these means the rank representations of the reliability of the available data support over the range of all input variables were sufficiently spread across the range of 10 to 0. The adjustment of the ranks provided a clearer discrimination of reliability by the user. Differences between the behavioral output variables or across the range of an input variable were thereby clarified. 4.4 Diagnostic Program After defining the reliability ranks for all input variables for each of the behavioral output variables, a diagnostic program was ieveloped to organize and designate the appropriate ranks. The diagnostic program contains all rank values, selects the appropriate rank for the input variable(s) called by the user, calculates a Composite rank for multiple input variables, and delivers a rank for each output variable and each iteration of the main model. The diagnostic program is composed of a controlling unit, the eight subprograms generating the reliability ranks, and the manipu- lative subroutines (see Figure 4.3). The controlling unit is small 71 DIAGNOS Controlling Subprograms Subprogram Generating --------------- Behavioral _> Sequencing _‘ Ranks _______________ a! (one @ for IL, IF,EL,PEI,EF, Display PE,PI,PM) ZERO REST RFALL resets calculates "‘ " stores internal output ranks values ranks to zero 0 Figure 4.3 General Diagram for the Diagnostic Subprograms 72 and simply controls the order of implementation of the subprograms, loads the rank output matrices, and provides for a rank output display. The eight subprograms containing the rank values for each input variable are the backbone Of the diagnostic program. There is one subprogram for each behavioral output variable: IL, IF, EL, PEI, EF, PE, PI, and PM. Within each subprogram, a value other than the preset dummy value for any input variable generates a rank value. IF statements are used to test for the presence of a reset value of each input variable. In general, there is at least one IF statement for each input variable. If no data were available for a given input variable or for a part or its range, the rank setting statements for that input variable are bypassed. The omission results in the assumption of a zero rank, as the ranks are initially zero. When a rank value is set for an input variable, it is transfer- red tO the RFALL subroutine, that stores all ranks for each iteration Of the model and for each behavioral rank subprogram. RFALL holds the reliability ranks in an array as each rank for the different designated input variables is passed from a rank subprogram. When a rank subprOgram has sequenced to the end, RFALL passes the rank array to the processing subroutine, RFST. RFST finds the minimum rank and calculates the average rank. The mean Of the minimum and average rank is also calculated. The minimum-average mean is a compromise for the weaknesses inherent in both the minimum and average rank. The minimum rank too frequently is zero, which prevents discrimination among the different variable combinations and between output variables. With multiple input 73 variables, zero minimums were a frequent occurrence. The average rank has good discrimination, but it does not accurately reflect the reliability. In a multivariate system, the weakest element - the one with the greatest variability and least reliability - determines, in large part, the reliability of the whole. The minimumraverage mean rank reflects the attributes of both, but reduces their weaknesses. The frequent minimum zero is eliminated and'the average is lowered. The minimum, average, and min-av. ranks are passed through COMMON to the controlling unit for storage in the rank output arrays. The control unit then zeros all designated ranks, using the ZERO subroutine, and calls in the next behavioral rank subprogram. This process continues through the eight subprograms, storing the ranks for each subprogram in turn. Finally, after the display of all output variables on one page, the three rank arrays are displayed by the behavioral measure and behavioral series on the following page. The entire process is repeated for each iteration of the model. 4.5 User Information The male sexual behavior model provides information on the effects of intrinsic, stimulus, behavioral, sensory, hormone, and drug effects on the sexual behavior Of the male rat. Eight behavioral measures are presented, along with two penile measures and three blood hormone concentrations. An estimate of the reliability of the output for each behavioral measure is provided in conjunction. 74 Input The user can input any combination of the 112 variables incorporated in the model. A complete description of each variable and their preset values is given in Appendix A. The input variables are of three general types. The first is the simple variable, that is only one experimental condition, such as age (A) or sexual experience (SEXEXT). Almost all the simple variables are real variables, so their values exist on a continuum. The second type is integer variables that set one of several closely related experimental treatments. The SEXSTIM variable, that can access any one of 15 different stimulus treatments - most involving the sexual object - is an example. The third type is a variable that is associated with another variable. The associated variable can give a more specific condition of another variable, as the ISS variable sets the intensity or frequency of shock for the ISHOCK variable, that sets the general shock condition. The remaining associated variable categories refer only to hormone treatments. An associated variable may establish a general hormone treatment condition; only a few of these exist (DPC, INJl, and HPI), but a value for each is necessary for the calculation of the effects Of the hormone treatment variables. The default values for each are all zero. Therefore, the default condition sets DPC, the time between castration and treatment, at the day of castration (a maintenance regime), INJl assumes one injection per day for the duration of treatment, and HPI sets sexual testing immediately after AD v. v 9'- Q— 75 injection. The last associated variable category is the internally related variables. A hormone treatment condition frequently has two neces- sary variables, one variable establishes the hormone dosage and the other the days of treatment. For'example, estradiol benzoate (EB) injection has the dosage variable, DEB, and the duration variable, EBDY. The user should check the'variable list for the dose and day hormone variables and designate a value for both to be assured of intelligible results. However, not all hormone or drug conditions have both variables; in that case, the one is sufficient. The next consideration is the incremental value required for most input variables. The model program executes a designated number of iterations, that increments each variable by the set amount Of each increment value for the designated input variable, and then recalculates all output variables. When the program reads in a value for an input variable, it expects a value for the increment as well, assuming an increment variable exists for that input variable. The increments are all real elements of an array, and exist for only real input variables, that are in the majority. All increments are preset within the program, almost all to a zero value (see Appendix A). The example in Table 4.4 shows the exact nature of a hypotheti- cal input utilizing data cards. This example demonstrates all the basic input requirements the user need follow, although as an input list it is more complicated than most people would want. The first value (5), on the first card, is the number of desired iterations. The program will recycle five times, adding increment values for all variables each time. Each increment represents another experimental 76 Table 4.4 A Sample Input Variable List Column NO. Card No. 7 10 15 20 30 1 5 2 A 3 300.0 7.0 4 TDN 5 13.0 -1.0 6 EICI 7 , 5.0 1.0 8 NEICI 9 10 10 NSEN 11 1 10 12 DPC 13 30.0 7.0 14 DTTP 15 150.0 0.0 16 DYTTP 1? 7.0 7.0 18 HPI 19 5.0 0.0 20 FLAG 13 a s be 77 test of sexual behavior. After the iteration value (NINC) cOme the input variables. The name of the input variable is given first (starting in column 7 of a card), and the values for that variable and its increment follow on the next card. The sequence is repeated for each variable. The final data card must be FLAG, which terminates the read-in of the variable names and values. The number of iterations (NINC) is read according to the format (7X,I3) for integers, so the last digit rests in column 10. All the variable names start in column 7, and are followed by the variable values. The values enter under one of three formats depending on the nature of the variable. In the example (Table 4.4), A, TDN, EICI, and the hormone variables (card 12 and below) enter according to the (lOX,2FlO.3) format, so the variable's real value is placed between columns 10 and 20, and the increment's real value between columns 20 and 30, in decimal form. In the case of the age variable (A), the males' age will be 300 days, and on each successive test-increment the males will be 7 days older. The TDN variable demonstrates that the increment can be negative, as well as, positive. The EICI and NEICI are associated variables that should be designated together for the enforced interval between intromission condition. The EICI sets a 5.0 minute enforced interval for the first sexual test, and the 1.0 increment increases the interval by one minute with each successive test. The NEICI - 10 establishes that the interval is enforced between each intromission in an ejaculatory series. As the NEICI variable is integer, it has a 78 different format, i.e. (10X,I5), which has the last digit fall in column 15. The NSEN array is a unique case. It has 12 elements, each a different sensory treatment. The array allows more than one sensory treatment to be designated. The NSEN array is filled according to a (6X,l3I3) integer format. As the array is preloaded with neutral integers, the user need only put in the values for the desired treatment(s). The example shows two treatments requested for NSEN: the OBX (NSEN-l) and noise during testing (NSEN-lO). Three columns are allowed for each integer value. The remaining variables are hormonal and use real variable designations for the variable and its increment. Table 4.4 includes the remaining two categories of associated variable. The DPC and HPI set the general conditions for the generation of hormone responses. DPC - 30.0 designates the initial sex test at 30 days following castration, a hormonal recovery situation. HPI - 5.0 indicates the test start at 5 hours after injection for that day, and as its incre- ment is zero; the subsequent tests occur at the same time following injection. Note that the increment for the DPC is consistent with the age (A) increment. It is preferable to keep all variables and increments consistent with one another, but not a necessity - the program will realign inconsistent values in most cases, but the realignment may not necessarily be what the user had intended. The DTTP and DYTTP variables are internally related. Both should be designated for guaranteed results. According to the values for the variables, a dosage (DTTP) of 150 ug/day with no change on repeated test-increments is set, and the first test occurs on the 79 seventh day of daily injection (DYTTP = 7.0) and retesting occurs once each week, an increment of 7.0 days. This day increment, again, is consistent with the A and DPC increments. FLAG terminates the list of variables. The program proceeds to calculate the behavioral, penile, and hormonal responses to these stated conditions. Output The output is in two major segments; one gives the behavioral, penile, and hormone values, and the second gives the reliability ranks for the behavior. The two segments are provided for each representation of a sexual behavior test, that occurs for each program iteration. Therefore, with an iteration value of 5, the output would consist of a single page statement of the number of increments and a list of the designated variables and their Lincrements, followed by the six sets of the two segments, one segment to a page (see Figure 4.4). The first segment provides values for an experimental and cr>ntrol male group. The behavioral measures include the IL, IF, EL, P131, EF, PE, PI, and PM. A value is given for each measure for the C<>ntrol and experimental male groups for each of the five consecutive eJaculatory series designated in the model. (Alternate series nNumbers are Obtained by changing the NSR.input variable.) In addition, ancillary behavioral values and the Experimental/ (RDntrol (E/C) group ratios are supplied. The ancillary values 31nc1ude a calculated intercopulatory interval (ICI), that is the HALE SEXUAL ataavton OAIA CPH 1.0000 1.0006 1.0000 1.0000 PH 1.0000 1.0000 1.0000 1.0000 CPI PI .9996 .9958 CFE PL .9956 [F 6.0 CPEI 319.99 PEI 323.70 CIF 13.00 IF 11.0) CIL 07.55 IL 07.55 $0 .9996 .9953 .9966 .9629 002.50 002.50 .9629 6.0 6.0 6.0 372.67 012.76 235.36 235.36 5.10 5.50 5.90 6.30 5.10 5.53 5.93 6.30 0.00 0.00 0.00 0.00 .9828 .9506 .9060 .9823 .9506 .9060 .8637 .6996 .5172 .8637 005.23 093.13 507.00 270.00 270.00 3 0 530.70 .6996 270.95 270.95 .9608 .9608 6.0 .5172 625.70 693.30 309.95 309.95 5 ANCILLARV BEHAVIORAL VALUES SERIES: CONYROL Gnu—0 CALCULATED BEHAVIORAL EIC RATIOS 80 SERIES: (EDIEDIII1=3\II GINEDlilflflii- GD!:DI:I¢=|¢I Denma— .10... Gaumnu II II II I. II 0 OCH30-o whom-b puma-c dl‘lldlIlflI IIE¢IIGIEII§ _ B-WHJU u-«uua HORMONE AND PENILE DAIA IHLI 92 $0! 2. :0 ml! ICSIOSICRONEINGIFLI 7.296 NO. 1 OF HORMONE NODEL CYCLES N0. HORMONE AND PENILE EIC RAIIOS Figure 4.4 Sample Model Output for a Normal Control Male Rat Group. 81 m.m m.m m.m o.o 9.0 m.m m.m m.m ¢.~ Q.~ n.m m.m n.m c.~ .ou tn Av.p:oov 3.: Onsmaa o.m o.m o.m @.m 0.0 o.m o.m o.m e.m o.m o.m @.m o.m o.m mom me a.— ~.— ..~ o.~ o.~ n.n o.n £.n °.¢ ~.. N.N c.~ m.“ c.~ o.n we 9.: 9.0 0.0 0.: s.“ 9.0 9.0 5.: m.~ m.~ mx2<¢ tat—Zn: coo c.c c.o coo 0.. mxz<¢ o.e c.o o.o 99° n.n mu mxz<¢ u—hmochuo a.n c.n m.n 5.. 0.. no u¢¢¢u>¢ o.~ m.— o.” c.n ..n nun 0.0 9.0 o.a e.o o.m ~.N h.N h.~ o.n ~.m m.~ n.n n.u o.~ u.m 4w 5.0 9.9 9.9 @.~ o.~ 0.. 0.. 6.. c.m o.m n.N n.~ now —.0 c.n u— 9.9 9.9 9.9 coo my" 9.9 o.o 9.: 0.6 $.N o.e o.c c.e 9.9 ~.~ 4— HNnC‘In acumen CnN'OOID 82 average number of seconds required for each intromission (EL/IF), for both experimentals and controls. The other ancillary values provide the average response of the IL, IF, EL, and PEI for experimental males when the non-responding males are included in the measure average. These total male averages are generated by multiplying the appropriate male response ratios by the behavioral measure, which is the P1 with the IL and the PE with the others. The BIG ratios are provided for all behavioral measures. Separate ancillary and E/C ratio values are given for each of the five ejaculatory series. The remainder of the first segment gives the hormone and penile data. The systemic blood concentrations are provided for T, LH, and FSH for the experimental males. The number of penile papillae in cross-section and the penis weight follow. The number of hormone cycles refers to the number of times the model had to readjust the LH and FSH levels against the T levels to obtain reasonable correspondence, particularly when the plasma levels are input variables (i.e. PLT, PLLH, and PLFSH) or dosages of any of the three are input. Furthermore, the E/C ratios for all the hormonal and penile measures are included. The second segment reports the filed reliability values for the particular combination of input variable values designated. A rank value is given for each of the eight behavioral measures in all five ejaculatory series. The reliability values are ranks from 0 to 10, and these are presented in three categories. The different categories are used to give a clearer picture of the reliability when more than one variable is utilized, as, internally, one reliability rank is designated for each input variable value. The bottom 83 category is the minimum rank; the middle is the average rank - the average of the ranks for each input variable. The top category is a combination of the average and minimum rank; it is an attempt to reflect the strengths of the minimum and average ranks and reduce their inherent weaknesses. Reference to the top rank category is usually sufficient for an estimate of the reliability of each behavioral measure output over the five ejaculatory series (the highest rank value is the highest reliability). The entire sequence of information is repeated for the next iteration and each following iteration. At the last iteration, the model terminates. For another sequence of input variables, the model must be reaccessed. Chapter 5 Effects on the Post-Ejaculatory Interval (PEI) 5.1 Introduction and Description The post-ejaculatory interval (PEI) measure chapter provides an in depth view of the effects of all input variables with data support on the PEI. The manner these relationships are handled within the model and the decision processes involved is the sole emphasis of. this break-down. The remaining male sexual behavior measures are discussed in a condensed fashion in the following chapter. By definition, the post-ejaculatory interval is the duration (in seconds) from an ejaculation to the first intromission of the follow- ing ejaculatory series. The PEI is a behaviorally quiescent period characterized by an inactive male rat, usually reclining in a corner of the testing arena, emitting an ultrasonic series of tones, termed a ”post-ejaculatory song” (6,7). For the purpose of standardization, a normal male is considered to be at least 100 days old, sexually experienced, and tested no more frequently than once a week at approximately five hours into the rats' dark period with a sexually receptive female rat. The PEI of a normal male ranges from 100 to 800 seconds, or 1.5 to 13.5 minutes. The normal male PEI increases in duration following each successive ejaculation. This pattern of increase pertains to a group of males; individual males are more varied in response. A composite of 55 studies,published in a variety of journals provides the normal 84 85 male values for the successive PEIs. The first (PEIl) through the fifth (PEIS) post-ejaculatory intervals are considered. 5.2 Effect of Successive PEIs A pattern of increasing PEI values with successive PEIs was demonstrated using data from studies reporting two or more consecu- tive PEIs. Multiple reported PEIs were required because the variance among studies resulted in different patterns when all studies, in- cluding those reporting only one PEI, were averaged. The mixture of studies with one or more PEI value(s) was considered less reliable, as far as the changing PEI pattern was concerned. Twenty-eight articles reported more than one successive PEI. The distribution of articles by strain was unequal. Many utilized Goteborg males (4,89,119,125, 130; N-l7 experiments). Less utilized Long-Evans males (41,62,65,74; N-4), and only one study each used Charles River (170), Sherman (52), and mixed hooded and albino (30) strains. An average value for each of five consecutive PEIs was calcula- ted based on groups of males with five or more consecutive PEIs. This included theborg (119; N-6 experiments), Long-Evans (62,74), and mixed (30) strains. The following equation, PEI“ = 38'SR°1n(SR) + P1311 fit the overall data nicely. The pattern was a logarithmic increase with consecutive PEIs, starting at the value given for the first PEI (PEIl). (SR refers to the number of the PEI following the desired ejaculatory series.) This pattern held for all strains (see Figure 86 600 - 500 - PEI ‘ value (sec.) 400 — — ll, — Model Curve 300 __ /* *---—* theborg //’ A—--A Long—Evans _ / +___,+ Mixed Strains - Ill 0 --- 0 Two Minor Strains *1 (CR, Sherman) ‘ 1 2 3 4 5 Consecutive PEI Number Figure 5.1 The Relation of Strain Averages to the Calculated Model Curve for Consecutive PEIs. The model PEI1 was based on the average PEI1 for all studies regardless of strain. 87 5.1). For descriptive purposes, the value of the calculated curve in Figure 5.1 was based on the average value for all strains at PEIl. The calculated curve and those for the different strains can be seen as essentially parallel, even though the initial PE11 value varies. Because each strain had a different first PEI value average, the PE11 value was set within the model by strain. The calculation of succeeding PEIs proceeded from that value. 5.3 Strain Differences The average PEII was compared between the different available strains (Figure 5.2 & Table 5.1). The Cgteborg males recovered from the PEI passivity the most rapidly, with Long-Evans and Wistar males at intermediate durations, and the slower Sprague-Dawleys had the longest PEIs. As might have been expected, the mixed strain group fell in the middle range. The PEI response was considered different if the standard errors of the means between two strains did not overlap. Therefore, the theborg (G) PE11 value was set at 240 seconds, the Long-Evans (LE) and the Wistar (W) at 320 sec., the Sprague-Dawley (SD) at 480 sec., and the mixed strains (M) at 370 sec. These were all approximations to the nearest five seconds. The articles involved appear in Table 5.1. The differences among strain PEIs was observed to have a genetic basis. Dewsbury (66) found by crossing four different inbred strains that the F1 generations had shorter PEIs than the average between the two parent strains, even though the F1 PEIs did fall between 88 Table 5.1 The Average Normal PEI1 Values for Different Rat Strains. Strain PEI1 (i t SE) N Bibliography No. theborg (G) 240.0 t 9.1 17 119,125,130 LongéEvans (LE) 319.8 1 11.5 7 41.62.65.74 Wistar (w) 319.3 3 12.6 16 28,137,138,102,144, ‘ 146,179 Sprague-Dawley (SD) 082.0 1 59.3 6 101,205 Mixed (m) 371.1 3 22.4 7 26,30,38,52,171,179 89 -1r- 500 o .—J_. 400 Value (sec .) I I 300 ‘ 200 G LE SD W M STRAIN Figure 5.2 The PEI1 Mean and Standard Error for Five Rat Strains. The actual values are given in Table 5.1 with other pertinent information. 90 those for the two parent strains. The lowered value would be expected on the basis of heterotic inheritance. Genetic effects were more noticeable for other behavioral measures. The indication of genetic components to the PEI gave further support to the decision to provide different PEI1 values for different strains. 5.4 Effects of Age The very young and the old males had longer PEIs than the normal adult males. PEI values were highest around puberty and fell rapidly to adult levels. Similarly, as males approached "Senility”, their PEI scores increased. From puberty, the PEI fell exponentially (Figure 5.3) to adult levels by 150 days of age. This pattern was approximated by the equation: PEI: =- ((0.12°(A-l70))2 + 225)/235 ; r Z 1.0 at A < 170 The equation provided a value for the ratio of Young/Adult male PEIs, for ages (A) less than 170 days. The exponential rise with decreasing age from 170 days was established by the square of the difference in age from 170 days. As the equation was originally derived from actual PEI values, a division by the normal PEI (235 sec.) for adults was necessary to provide a ratio applicable to any group of males. The young age equation was derived from the average PEI values for theborg males. Four groups of males reported in two studies (119,140) provided data ranging from 80 to 426 days of age. The range of 158 to 426 days was assumed as the adult range as no 91 .wofinomopmo own 05 mafia: .9323on one 203...“.on own one :flomopmo 0mm MESA on... .Hom mfinmeoapmaon one mnemmxo phones one .33 was: mom 03mm Howe: HHmm one so om... mo poommm mam. m6 0.5me $3.0 m3 0% onm 8m. onm 8.0 3% 8M om: 2.3 0mm 0me 0mm 0.0... 0.3 0.3 we ACTH I HEHV = 9.0 - a. t< w::o> :04 04 + mmgonsévmio u HE“ . . 3 A933 m2 638 03 on.“ 0.3 3H 8H om on ow on . _ h a _ _ _ O.H . NA In; 1 j . HHE mm~\_flnmm + mzofilémdom u I mg a. M::O> fl m4 r 9m 92 consistent increase or decrease from the average PE11 value of 235 sec. was noted. Therefore, the 235 sec. value was equivalent to an r-1.0 ratio value in the equation. 4 Other researchers provided data on young males, but they reported only one or two data points in the young age range, and none in the adult range (170-450 days). Therefore, comparisons of young- adult age differences due to strain differences were not available. (The articles included by strain: G - 87,89,127; LE - 42,45,58,61, 62,64,65,74; SD - 205; W - 28,158,179,181; and M’- 26,179,201). The primary problem in interpreting age data was the potential interaction with sexual eXperience and repeated testing. 4The available data for age effects was based on repeated testing of the same group of males, thereby providing a series of data points of increasing age. The higher PE11 values at the earliest age of 80 days might, in part, be due to a lack of sexual experience. Sexual experience would have increased with repeated testing at the same time age increased. The same relation would hold for the males' familiarity with the testing environment. No experimental separation of these factors has been carried out within the published PEI data. Dewsbury (65) repeatedly tested males approximately 125 to 150 days of age and found no obvious change in PEI response. This, however, was weak evidence for a lack of experience and/or testing effect. The age range was far too narrow to show a noticeable age interaction. In addition, the age range made the comparison of the Dewsbury strain (LE) with the age equation strain (G) ineffectual. A representation of the variation of the reported data points about the model curve was established using the mean and standard ,wqwz—f'v 93 error of the deviations of the Experimental/Control ratios from the model value. The variation with age of the young males was not consistent. Before 95 days of age, the variation (0.23 1:0.04) was slightly larger than that for 95 to 145 days (0.16 i;0.03). No consistent pattern of change in variation was seen over those ages. The change in variation was consistent with behavioral expectations. The PEI response was more variable at earlier ages, consistent with improving performance due to both maturation and acquired experience. The effect of age upon the consecutive PEI increase was negligi- ble for young males.‘ The patterns of PEI decrease with age were parallel when consecutive PEIs were compared. PEIZ was consistently longer than PEII, as PEI3 was longer than PEIZ, and all showed the exponential increase approaching puberty. Similarly, the pattern of PEI increase due to consecutive PEIs (seen in Figure 5.1) showed the young response parallel to the adult male response. Therefore, no interaction between consecutive PEIs and early age was concluded. A better indicator of the lack of a consecutive PEI - age interaction was the deviations from the established curves. The deviations were similar for PE11 through PETS. In fact, a slight decrease in the deviations existed with increasing PEI number for all available points (62,74,119,120,l40). The variation for PEII was 0.20 110.03 (n-15 points), and the range of the mean deviations for PE12 through PE15 was 0.14 to 0.18 with the deviations standard error range of 0.03 to 0.04 (n-13-15 pts.). The variation was con- sistent about the calculated model values for all five PEIs in the range of the young ages. 94 The adult males aged approximately 145 to 475 days or about 5 to 16 months (Figure 5.3). As the adult age group was the normal standard of comparison for young and old ages, the relevant information has been described in the previous sections. The model ratio for the adult was 1.0, and no changes occurred in the adult age range. However, the variation with increasing PEI number was a consideration. The Goteborg strain (4,119,123,124,125,130,132) had somewhat less variation (0.16 :_0.03, n-l8 for PEIl to 0.11 1 0.02, n-10 for PEIs) than the combination of the other strains; LE (64), SD (171), & M (30); with deviations of 0.27 :;0.11 (n-23) for PEIl to 0.18 :_0.06 for PETS. As indicated for the young males, the same decrease in deviation occurred with the adult consecutive PEIs in all strains. The effect of increasing old age, "senility", on PEI values was more limited than for the decreasing age pattern of the young. After 450 days of age, males showed a gradual linear increase in the PEI. The relation was represented by the equation for the line: PEI =- 0.42'(A - 450) + PEIa ; for A > 450 old dult The equation stated that for each day beyond 450 days of age (A), 0.42 seconds were added to the PEI value for the normal adult. Unfortunately, only data for theborg males (119,124,132,140) was available; thus, again, strain comparisons were not possible. The old males displayed no interaction between age and the consecutive PEIs like the young males. The consecutive PEI increase for old males was parallel to that for the adult. In addition, the pattern of PEI increase with age was parallel from PEIl through PEI5. 95 The variation about the old age model line established a slight decrease with consecutive PEIs (Table 5.2) like the adult. The reasonable similarity in the deviations indicated the equation line adequately represented all five PEIs and not just the PE11 data, from which it was originally derived. The variation across the age variable from 501 to 821 days of age (16.5 to 29 months) had no consistent pattern. The weighted average deviations of the 10 different ages in this age range was 0.122 1:0.028 (n-B-S pts/age). Table 5.2 Deviations from Five Consecutive Model PEIs of Old Males. PEI # Deviations (X t SE) Npts 1 0.135 1- 0.022 10 2 0.137 i 0.022 10 3 0.119 1 0.028 10 4 0.082 1 0.022 5 0.110 1 0.042 Over the entire life of the male rat, the PEI response exhibited an extended "U" shape pattern; the rapid decrease from puberty leveled out to an adult low plateau that at later ages developed a gradual increase in PEI length (Figure 5.3). In none of the three age categories was any interaction observed between age and consecutive PEIs. The variation about the model values further demonstrated the reliability of age effects across five successive 96 PEIs. Any relative effect of strain was left open to question, as only one strain provided sufficient data for the establishment of age patterns. 5.5 The Time of Testing The hour of the day of sexual testing was expected to have some effect on sexual performance. The male rats' period of greatest activity was the nocturnal hours. Similarly, the rat was internally affected by daily circadian rhythms, that influenced neural functioning and blood hormone levels. Comparisons of sexual responses during the same relative times of the dark and light periods were reported (63,119,123). Larsson tested both young (4-7 mo.) and old (14-16 mo.) males during the first four hours (123) and from the third to the eighth hours (119) of both the light and dark periods. The rats were kept on a 12 hours of light and 12 hours of dark (12L:12D) cycle. PEI values were higher during the light period than during the dark period in both studies. The PEI values were significant (p < 0.05) for PEIl_3 for the young males. As demonstrated during both the day and the night, but the effect of day testing was in the same direction in both age groups. No age interaction was indicated. The Day/Night ratios were calculated within each experiment for comparison. The overall ratio for PEI1-5 was r - 1.19 for the younger males (123), an average of the three available ratios (1.148, 1.348, & 1.085). Curiously, the effect of day testing was significant for the normal light cycle, but when the same males were 97 later tested under the same regime on the reversed light cycle, no statistical effect was evident (119). As before, no effect was seen on consecutive PEIs. The Day/Night ratios showed no consistent change over the five consecutive PEIs. Similarly, increases with consecutive PEIs were parallel when the day . and the night tests were compared in the young males. No interaction was assumed between the consecutive PEIs and the time of testing. The older males displayed an alteration of the young male responses (123). The older males had a higher average Day/Night ratio of r - 1.34 for PE11_4. However, statistical significance was found only for the third PEI. Because Larsson reported no test for interaction between testing time and age, an assumption of difference between the old and young Day/Night ratios would be unsupported. However, the ratios for both the young and old males ‘ were included in the model. No obvious differences between young and old males were seen in the raw PEI (sec.) scores. Also, the variation about the Day/Night ratio average for each group showed no real differences (dev. - 0.086 :1; 0.035 for old males and dev. - 0.094 1 0.023 for the young) over four consecutive PEIs. The parallel increases with consecutive PEIs held for both young and old. Although testing during the rats' daylight period prolonged the PEI response, no data demonstrating changes during the light period were reported. Only Dewsbury (63) has demonstrated a possible change during the dark period. The PEI was reported at its highest level just after the lights were turned off, and the PEI continued to decrease until near the time the lights were switched on. In two 98 experiments, Dewsbury (63) tested for male sexual behavior at two and four times during the dark period. The tests at different times were separated by one week and balanced according to a Latin Square design. The change over the dark period for the combined experimental data was represented by the equation: -O.23'TDN + PEIl(sec.) = 240'e 240 The equation described a decelerating decrease in PEII values from a high of 480 seconds at lights-off (TDN-O) to a low lights-on of 240 seconds (TDN-lZ). However, for wider applicability and use within the model, the equation was converted to a ratio equation. The above equation was divided by 320 seconds, the value approximate for both experiments at five hours after lights-off (TDN-S). Four to six hours into the dark period was the most frequently reported time of testing. Therefore, at TDN-S, the PEI ratio was set at r=l.O with an increasing ratio at less than TDN=5 and a decreasing ratio further into the dark period. The equation became: rpm - 0.72';-e'0‘23'TDN + 0.75 ; for TDN 5 12 Although this ratio equation was known to fit only the PEIl, it was assumed effective for the later, successive PEIs. The assumption was based on the independence of the consecutive PEI rise established in the previously discussed variables. No pattern during the light period was assumed for the model; only the overall ratio (Day/Night) over the entire period was reported. 99 5.6 The Time Between Tests (TBT) The time between consecutive tests (TBT) of sexual behavior, the first of the independent testing variables, caused PEI increases when shortened (Figure 5.4). The degree of increase was less pronounced for the first PEI than for subsequent PEIs. To accommodate this finding, two equations were required: -O.833(TBT - 0.5) + 1 r - 2.6'e .0 ; for PEII r - 2.6°e + 1.0 ; for PEIz-5 Both equations described an accelerating increase in the PEI ratio (experimental TBT/30 day TBT) with reductions in the time between tests. The difference between PE11 and the remaining PEIs was one of degree rather than kind. The general shape of the equa- tion generated curves was the same, but the exponent for the PEIl described an acceleration of almost twice that for PEI2_5. As a result, the PEIl ratios became lower when the duration between tests was extended than the later PEIs. The ratios used to generate the equations were the short TBTs divided by the long control test separations. For each particular study a period of at least two weeks (TBT-14 days) was considered a reasonable control period. The available studies had 15 (30), 30 or 60 (119) days between tests for the control. One study had a maximum TBT of 7 days (76). The ratios for this study were adjusted according to the 7 day level of the other studies. All sexual tests were extended to sexual satiety (30,76,119) or 90 minutes (30). No information was available for shorter test lengths under this 100 mem one poops manaom oapmn 9o soapspanpmad on» macro vowed one .mcwonpm econommav onp How o>nso codpmsuo . Ham corp Hopoonm mHmm o>apsoowcoo was HE .moflomBoo HE 9n. E 03am {a 65 3 393 momma coozpom 25a. 65. .8 833% one in magmas $.33 ems cu m m h o m v m . N n In», 04 + Am.uem.avmmw.uo w.m u Ham.“ 01.13-502.12. a... ma :2 in A933 ems 39$ Cor. m m km F ’ ’ b b # ’ 1T +. coach: .9. HaomHmH 0 wcm>m¢wcoq .0. 3238 * figm pom o.H m4 moapmh o.m o\m m.m Ham 0.9 Wm 0.: 101 experimental treatment. The remaining study provided the shortest intervals between tests (30), the various intervals within a 24 hour span between two 90 minute tests. The ratio data points used for the PEIl equation fit appear in Figure 5.4. The model curve reasonably followed the distribution of points. The degree of deviation of the data was separable into two categories. The average deviation for the TBT less than or equal to one day, contained within one study (30), were 0.658 : 0.178 (2 t SE, n-8 pts.). For TBTs greater than or equal to one day (76,119), the deviations were 0.292 :_0.081 (n-ll). The deviations about the equation values were clearly greater before one day between tests than after. However, it would be unwise to assume the difference in variation was due to strain differences (LE vs. G or M). The higher variation was more likely due to the effect of the closely timed test interval. With shorter intervals, the distinction between two separate tests and one extended test tended-to fade, and as the males approached sexual satiety in an extended test, their responses became more variable. The ratios used for the second TBT-PEI equation were based on an average PE12_5. Only data (30,76,119) for TBTs of one day or more were available. As expected, the greater variation about the second equation occurred at the shorter test intervals. The deviations were greatest at TBT-1 or 2 (0.403 i_0.216, n-6 pts.), decreased slightly for TBT-4 and 6 days (0.327 :_0.090, n-6), and drapped to its lowest (0.130 :;0.018, n-ll) for greater than 13 days. The degree of variation was similar to that for PEII. A definite effect was found for the duration between tests of 102 sexual behavior. Adult males showed longer PEIs as the interval shortened, and the effect became negligible at intervals of 5 to 6 days for PEII and 9 to 10 days for PEI2_5. When test lengths were at least 90 minutes or to satiety, these patterns of effect held. The TBT patterns may have attenuated when test durations were shorter, i.e., testing to only the end of PEIl, perhaps, propor- tional to the test length. However, no data were available using shorter test durations. This was unfortunate, because most tests of sexual behavior were less than 30 minutes in duration. Furthermore, as the interval between tests decreased, the variation in PEI response increased for all PEIs. 5.7 Sexual Experience Effects The repeated testing of the same group of males created a confusion of sexual experience effects with those of maturation (age). Several studies (48,64,119,158,l69) provided information on changing sexual experience with repeated tests. However, only one, study (127) tested males of the same age with differing sexual experience. Unfortunately, no study of repeated testing effects was available, a test that would have involved testing experienced males over the same testing regime as inexperienced males at the same age. Larsson (127) tested males with three prior sexual tests (SEXEXT-3) as males of the same age (135-138 days) with no prior experience (SEXEXT=O). With age controlled, PEIs were reported shorter for males with prior sexual experience, but the effect was not statistically significant. However, a significant decrease in 103 PEI occurred from the first to the second test within the inex- perienced group; a similar drop occurred for the experienced group, but it was not statistically significant. Some experiential effect was indicated. To further check for an experiential effect, studies (48,64,119, 158,169) of sexual experience of differing age were assessed. PEI both increased and decreased due to repeated testing. Admittedly, studies showing a decrease in PEI after the first test were in the majority. None of the studies reported finding statistical significance. Because of the doubt regarding the reality of sexual text experiential effects, the model assumed no effect on PEI. This conclusion was further indicated by the experienced/ inexperienced group ratios. Ratios fell both above and below the r-l.0 level. The relatively high deviations from the assumed r-l.O suggested a cause of the statistical unreliability. The average deviations for PEI 1-5 were 0.251 :_0.046 (n-l3 pts.). The deviations also demonstrated a lack of any effect of consecutive PEIs. The mean deviation from the first to the fifth PEI ranged from 0.234 to 0.274, with no consistent pattern over the five PEIs. 5.8 Early Housing Effects The housing of male rats from weaning (25-30 days of age) to adulthood had no differential effect on PEI regardless of the housing situation: isolation (one/cage), segregation (male groups), or cohabitation (mixed males and females). Three studies (87,139,206) 104 provided the data for the average ratios: Cohab/Seg . 0.935 (n-Z), Isol/Seg - 0.990 (n-2) and Cohab/Isol a 0.887 (n=3). The individual study ratios ranged from 0.780 to 1.118. .No evidence of a difference among the ratios or from the 1.0 standard ratio was indicated. The model reported no effect. 5.9 Introduction to Experimental Effects The following experimental variables differ from the variables discussed above because they are elective experimental treatments. The above variables are intrinsic to the male rat or to the experimental testing situation. The experimental treatments include the enforcement of an interval between intromissions or enforcing an interval for the post-ejaculatory interval, changes in the stimulus value of the female sexual partner, electric shock, conditioning paradigms for approach or avoidance, and alterations of the males' environment either before or during testing. The enforced intervals are considered first. 5.10 Enforced Intromission Intervals Creating a strict time interval between one or more intromis- sions (ICI) affected the subsequent PEI. The effects of enforced 1018 referred only to the PEI immediately following the manipulated . ejacuatory series. No data were available for the second PEI following the manipulated series of intromissions. The intromission interval was enforced either at one ICI or 105 each ICI during an ejaculatory series. The interval was enforced by removing either the female or the male from the test arena. All ratios generated for comparison were based on an ad lib. control male group, allowed no interruption of ongoing behavioral testing. The enforcement of one ICI during an ejaculatory series occurred after the first (42,119) or the fourth (42) intromission of the first series or after the first intromission of every series extending to sexual satiety (119). The PEI decreased as the result of an enforced ICI (EICI) of from 0.25 to 7.0 minutes. The effect of removing the male from the arena did not differ from removing the female (119). The decrease in PEI was maximal for the EICIs of one minute or more. The pattern of decrease from the i1.l$§' PEI to that at one minute (EICI-1.0) was not established by either study (42,119); the studies had no EICIS less than one minute. The PEI was low by EICIS of one minute and only a mild decrease occurred over longer EICIs. The data were represented by the equation: . -OOS.EICI rPEI 0.15 e +-0.85 The equation described a decelerating decrease from the control level, r-l.0, at EICI-0.0 to the minimum ratio, r-0.85, by approxi- mately EICI-7.0 (see Figure 5.5). The rPEI dropped two-thirds the distance to the minimum ratio by approximately EICI-2.0 minutes. The variation between the studies was rather high, so the variation around the calculated curve was high (dev. - 0.103 310.021, n=31 pts. over PEI No effect of consecutive PEIs was indicated. 1-4" The effect of the same length EICI for each intromission during 106 1.10 II ,1 After 1]: 1.05 , I _I I 1.00 ‘ | A 1 \ ‘ '. i“ I A « 0.90 I' ‘ PE11 I F» g ‘ ‘ \A 0.85 '| I EICI/ * ad lib. 1.05 Ratios 1.00 After All Is 5 6 7 EICI (min.) Figure 5.5 The Response of the PEI Ratio to Enforced ICIs after one Intromission or after all Intromissions in an Ejaculatory Series. The reported data points appear as symbols ( * theborg; A Long-Evans strains) and the model values appear as a heavy line. 107 an ejaculatory series was almost the same as for a single EICI in a series. Only one study (42) repeated the same treatment schedules for both enforced interval regimes, and neither study (42,119) tested for differences between the regimes. The Bermant study (42), because it used the same EICI intervals throughout a series, was given the greater weight in the equation formulation. . -O.75°EICI rPEI 0.22 e + 0.78 The multiple EICI curve decelerated more rapidly than for the single EICI (0.75 vs. 0.50 for the rate exponent coefficient), and the multiple EICI treatment declined to a slightly lower minimum ratio (rmin - 0.78 vs. 0.85, respectively). Because of the lack of consistency between the two studies, one (119) reporting no effect, statistically, and the other (42) a signi- ficant effect, no significant difference should be expected between the two model curves or the data supporting them. The high variation about both curves (mult. EICI dev. - 0.100 :;0.029, n-9 ; single EICI dev. - 0.103 :;0.021, n-3l for PE11_4) further suggested the lack of any distinction between the two treatments. Again, no indication of an interaction with consecutive PEIs was indicated. Larsson (119) found an increased PEI when males were tested to sexual satiety (two tests to one hour on two consecutive days) three days before a multiple EICI test. The PEI ratio was r-2.0. An effect of satiety was certainly demonstrated, but an EICI effect or an interaction between EICI and satiety remained unestablished as no satiety control was reported. Regardless, the rPEI - 2.0 was 108 incorporated in the model as an effect of the combination of EICI with satiety. 5.11 Effects of an Enforced PEI The procedure for enforcing a predetermined interval after an ejaculation was the same as for the enforced ICI; the female partner was removed for the desired period and replaced. The measurement of the PEI response when the PEI was arbitrarily enforced appears para- doxical. However, the PEI following the enforced PEI (EPEI) was the experimental PEI measured; the following PEI was always unmanipulated. The enforced PEI was usually the first PEI occurring in the test. The model assumed the EPEI after the first ejaculation. The EPEI ranged from 6 minutes to 72 hours, and two strains (LE (68) and '0 (121,122)) were involved. After 24 hours (EPEI-1440 min.), the enforced interval could be viewed as a time between tests (TBT) as easily as an EPEI. Therefore, the model will produce quizzical results if both TBT and EPEI are designated together at lengths of 24 hours or more. The pattern of PEI response following the enforced interval was a weak downward trend to approximately 200 minutes of enforcement. The best representation for the trend was the following line: r - -0.000625°EPEI + 1.05 ; EPEI < 207 PEI2 The initial, slight increase in PEI, described by the y-intercept (1.05), was indicated by Dewsbury and Bolce (68), but they did not 109 carry the EPEI beyond 30 minutes; they demonstrated no significant pattern, only a potential downward trend that was highly variable. Only the Larsson study (121) provided information for EPEI values greater than 30 minutes (EPEI - 15-240 min.). The falloff in PEI length became more rapid after 24 hours (122), following the relationship: rpm =- 0.55 + 0.50 ,[1—(1/(-1.19x10-4-EPEI + 1.515)) 2 The EPEI/ad lib. ratio accelerated downward to an approximate rPEI - 0.55 by 72 hours (EPEI-4320 min.), the last available data point. The fall in PEI after 24 hours treatment was possibly a consequence of enforcing the interval after the third ejaculation (122). The drOp was probably an approach to the PEI value of the first PEI of the next test. In other words, at some interval before 72 hours, responses apprOpriate to a time between separate tests developed. The ad lib. PE11 value for these theborg studies was about 250 seconds; PEI4 dropped to 252 seconds after the fourth ejaculation following the enforced 72 hour EPEI3. Furthermore, the PEI values for the experimental PEI4 and PE15 were exactly those for an 32 £12' PEII and PEIz, respectively. The best overall statement of an enforced PEI effect was at very low EPEIs the initial, slight, nonsignificant increase in the PEI was equivalent to the slight changes induced by handling. The gradual early decreasing trend was noticeable but would not prove statisti- cally significant without a large number of males. The longer EPEIs became equivalent to the separation between two different tests (TBT). 110 That the PEI following extended EPEIs approached the PEIl level of a second test was a reasonable assumption. Furthermore, I would expect the earlier in the behavioral sequence the EPEI occurred, the shorter the enforced interval required to attain the equivalent of a normal PEIl. 5.12 Change of Female Stimulus The female stimulus change involved exchanging the original female partner (same female) for a different female, having had prior sexual contact with another male (used female) or having no prior contact (fresh) that test day. The control group had the original female removed and replaced. No effect of a female change was found for PE11-5 (6,62,68, 77,101). The average different/same female PEI ratio was 1.056 (n85 pts). The average included both fresh and used females, as no discrimination between the two was made by any study. The ratios ranged from 0.966 to 1.026. The only actual effect of female change was to extend the duration of sexual behavior. Fisher (74) introduced a new female when the male reached sexual satiety (15 min. without a mount). The males left with the same female throughout attained an average of 8 ejaculations, but the introduction of a new female each time satiety was attained extended male performance to 12 ejaculations. The duration of the PEIs beyond the sixth series remained about the same. The PEIs attained a plateau at an average of 824 seconds, which was approximately the PEI value for the seventh PEI. lll Apparently, an upper limit existed for PEI duration. Because the model handled only PE11_5, it treated the female change as the beginning of a new test. Therefore, the model's PEI1_5 actually reflected the PEI7-12 from the Fisher study when satiety and female change were set. The model added 518 seconds to the value of the PEIl for normal males and held it for five PEIs. An alternative female stimulus was a female with the vagina sown closed (VagX), preventing intromissions. Hard and Larsson (88) allowed the males access to a VagX female for 40 minutes, while the control males were placed in a transparent cage in the test arena with a female for the same period. When both groups were tested with a normal female after the 40 minute treatment, no difference was observed between the two groups. The additional stimulation of mounting a female did not significantly alter the PEI. Intromissions and/or ejaculation were apparently necessary for the consistent increase in consecutive PEIs. 5.13 Electric Shock Stimulus Electrical shock was delivered to males with the expectation of stimulating sexual behavior. The intensity of shock was generally set just below the squeal threshold for each male, and the shock was delivered to the males' rear; back, flank or tail; through attached wires. Shock did reduce the length of the PEI. The average shock/no shock control ratio was r - 0.85 for PE11-3. No evident difference existed among the three consecutive PEIs (see Table 5.3) of six 112 studies (6,9,52,17l,173) - one study was considered twice as two different strains (LE 8 SD) were used in separate experiments. The Long-Evans strain was definitely in the majority (6,9,l7l,173). Table 5.3 Shock/No Shock Ratios for PEIl_3 PEI # Ratio (2 t SE) Npts. 1 0.859 i 0.021 16 2 0.848 10.033 4 6 3 0.872 i 0.045 5 However, no evidence was found of any strain difference when the ratios were scrutinized, nor was there any difference between the LE and SD strains in the one study (171) using both strains with similar treatments. No difference was observed for different shock rates. Caggiula and Vlahoulis (52) utilized rates of one and ten shocks per minute. Although both shock rates depressed the length of PEI1_2, the depression was the same in both cases. The addition of a bar press conditioned response to the shock treatment further decreased the PEI (173). The males were trained to press a bar to release a female into the cage for one intromission, then the shocks (1 every 30 sec.) started or the no shockfad_lib. condition ensued. The decrease in PEI was statistically significant under the shock plus bar press condition (Shk+BP/Shk-r-0.877), while the bar press condition alone was not significant (BP/ad lib.-r-0.928). 113 The two conditions appeared to be additive, although a minor interaction was possible. The combined effect of the two treatments provided the BP+Shk[ad lib. ratio of r-0.763. The effects were almost additive because when the ratios for the treatments taken independently were multiplied, BP[gd lib. x Shk/No Shk a 0.928 x 0.85 - 0.789, the result was not far from the effect of both (r - 0.763). The multiplication of ratios was for simplicity in modeling. The respective deviations from the 1.0 ratio were added to similar effect, (-0.072) + (-0.15) - -0.222, resulting in the additive ratio of (1 - 0.222)-0.778). The additive nature of the two treatments implied each was an independent effect. 5.14 Electroconvulsive Shock (ECS) Beach gthal. (26) provided information on the effect of ECS on PEIs. The shock was an electric current (65 mamps) applied across the rat's ears for 0.10 seconds, once a day for 12 days. ECS increased the duration of the PEI when the males served as their own controls (tests before and after the E08 treatment). Over 12 days of treatment, the repeated ECS treatments had a decreasing effectiveness. The ECS/ pre-post treatment ratio was initially r-l.15 after 4 days of E08 and fell to about the r-l.0 level by the 12th day of treatment. 4 rPEI 0.156 \/1.- (ECSDY/lZ) + 1.0 The equation described a downward acceleration of the PEI ratio. 114 The most rapid drop in rPEI occurred at the latter days of treat- ment (ECSDY) with ECS, and attained the no effect level, r-l.0, at 12 days of treatment (ECSDY-12). This relationship was incorporated in the model, even though another study using ECS might have demonstra- ted a different relationship or no relationship. 5.15 Conditioning Effects Male rats were conditioned to perform a task to obtain a sexual stimulus, usually a female, or to avoid elements of the sexual testing situation. Conditioning did affect latency measures such as the PEI. Larsson (119) had tested the largest variety of conditioning paradigms, attempting to alter the rate of sexual performance. One case involved conditioning copulation to the presence of a light. During the males' training, a light was turned on, the conditioning stimulus (CS), during copulation (the unconditioned response - UCR). After each intromission or ejaculation, the light was turned off and at the start of the next intromission, it went on again, etc. During the final test session, the light was on constantly. The PEI decreased compared to an ad_lib. control group. The effect, however, was not statistically significant, probably due to the low number of males (n-7) tested over three consecutive PEIs. The average E/C ratio was r-0.87. A similar conditioning regime was the linkage of a loud bell, an aversive stimulus, to mounting the female. The treatment included removing the male from the arena for one minute (EICIal.0) after each mount or intromission. The aversive conditioning caused a 115 decrement in behavioral performance; PEI scores were increased for PE11-3, but the increase was statistically significant for only the second and third PEI. The BIG average ratio for the three consecutive PEIs was r - 1.32. The ratio did not include any effect of the enforced interval; the control group experienced the one minute EICI, also. Males were conditioned to an operant response. Males were trained to pull a pedal (CR) for access to a female (UCS) in a modified Skinner box (119). The female was removed after ejacula- tion and further pedal-pulls were required for her reintroduction. To assess PEI effects, the.§2.l$23 copulation data was compared with the latency to initiate the necessary 10 pedal- pulls after ejaculation. When the conditioned response was initiated after each ejaculation or on selected ejaculations, no consistent pattern emerged. The pedal-pull latency was significantly lower than the PEI after ejaculations l and 6, but was not consistently lower following ejaculations 2 through 5. These data demonstrated that male activity could be initiated prior to the end of the normal PEI duration. It did not show a direct effect on the PEI. Because of the lack of correspondence between the pedal-pull latency and the PEI, this condi- tioning regime was not given a PEI value in the model (i.e. r-1.0). Other researchers have used a very similar operant conditioning paradigm for access to a receptive female. Both studies (104,173) utilized the bar press operant in a Skinner box to release the female into the box. The male was allowed one intromission before the female was removed, and bar pressing had to resume for another 116 intromission, etc. The PEI ratios (Cond./ad_lib.) were r-l.15 (104) and r-0.927 (173); both were nonsignificant. Therefore, the no effect ratio (r-l.0) was assumed. The exception was the combined effects of bar press responses and shock reported (173) previously in the section on the effect of shock. 5.16 Group Sexual Tests On occasion, more than one male and female were tested together in the same testing arena. Three G3teborg males (119,120) were tested with three females. The PE11_5 were not different when group tested males were compared with single pair copulations. The devia- tions of the Group/Pair ratios from the r-1.0 were very small (0.071 r 0.015, n-10 pts.). The model reported no change in the PEI. 5.17 Miscellaneous Stimulus Manipulations No effect upon the PEI was observed due to exposure of the experimental male to a copulating male and female prior to the experimental sex test (90). The experimental male was placed in a transparent box with holes that was placed in the test arena where a pair of rats were copulating for a period of 40 minutes. The control males received the same treatment with no copulating pair present. The nonsignificant E/C ratio was r . 0.95 for PEII. The model reported no effect. Electrical self-stimulation of the medial forebrain bundle - lateral hypothalamus resulted in nonsignificant change in the PEI 117 The male was trained to press a pedal (55) or lever (38) for 5 minutes (55) or to seminal emission (38). The resulting PEI ratios (E/C) were r = 1.024 (55) and r = 0.874 (38) for PEIl. As both studies found no statistical significance and the PEI ratios existed on both sides of the null value (r-l.0), the model incorporated no PEI change. Plastic collars, preventing genital grooming, also did not alter the PEI. Genital grooming normally would occur after every intromis- sion and ejaculation. The experimental, long collars placed about the male's neck prevented sufficient bending to reach mouth to genitals. A control, short collar allowed the grooming. The BIG ratio was r a 1.094 for PEIl (96). As the effect was nonsignifi- cant, the model reported no PEI change. Handling the male during the course of a sexual test was often a control condition for other experimental manipulations, such as the EICI or EPEI. Larsson (132) compared the behavior of males removed from the arena approximately twice a minute and replaced with males allowed to copulate without interference. No effect of handling was found over three consecutive PEIs for young males (5-6 months old). The average Handled/ad_lib. ratio was r - 0.997. However, when old Inales (20-24 mo.) were given the same treatment, a significant effect (p<.05) was found in PEI1_3. The E/C ratios fell regularly from r - 0.84 on PEIl to r - 0.76 on PEI3. The change over consecutive PEIs conformed to the line: rPEI = -0.04°SR + 0.88 (SR is the PEI number) Handling retarded the increasing PEI length that occurred with 118 increasing old age, creating a definite age - handling interaction. In addition, the inhibition of the age induced PEI rise increased with progressive PEIs. The inhibition of the age PEI by handling resulted in an actual approach of the PEI length to that of the adult male. 5.18 Introduction to Sensory Organ Manipulations The surgical removal of a sense organ or the sectioning of an appropriate sensory nerve was the usual manipulation of a range of sensory stimuli present in the sexual test environment. The reported procedures included the removal of smell by excision of the olfactory bulbs or the chemical destruction of the olfactory mucosa, the removal of sight by blinding via enucleation, and the elimination of somatosensory information by cutting nerves to the penis and penile anesthesia. Why no study of hearing was attempted remains a mystery. 5.19 Olfactory Bulbectomy (08K) and Peripheral Anosmia The bilateral removal of the olfactory bulbs was the primary I>rocedure for the elimination of smell. In a few cases, associated 'brain areas were removed, such as the olfactory tubercle (100) or the 'Olfactory peduncle (138). No obvious difference was seen among these alternative treatments. The surgical operation occurred when the 'males were 6 to 240 days of age, but the average treatment age was about 120 days. All articles reported some measure of the effectiveness of their technique. Some (l37,l38,l39,l68,206) made use of an odor 119 preference test, where the male had to locate a randomly placed, hidden food source. Other researchers made a histological check of the extent of damage to neural tissue (45,100) or a less rigorous, gross examination of the whole brain (98,139). A variety of rat strains were represented, and the majority of male groups were sexually experienced prior to OBX (45,98,100,l37, 138). However, three studies were assumed to use inexperienced males as the olfactory bulbs were removed at 6 (168), 30 (183), or 80 (139) days of age. An average OBX/control (sham or intact) was generated based on ratios from each study and experiment within a study. The average OBX/C ratio of one ratio per study was r - 1.253 (n88 pts.). The average ratio for all experiments was r - 1.248 (n-l6). The model incorporated a PEI ratio of rPEI - 1.25. The statistical significance of the OBX treatment for PEIs directly determined the reliability of the assumed model ratio. Unfortunately, only three Larsson studies (98,138,183), utilizing different strains, reported statistically significant effects. The significant ratios ranged from 1.23 to 1.86. Furthermore, only one of the nonsignificant studies (168) could be seriously faulted for the surgical technique, in addition to an overly low number of males (n-3) with Successful lesions. Although the majority of studies (45,100,137,l39,l68) found no statistical significance due to OBX, all the PEI ratios were above r - 1.0. The range of these ratios was 1.02 to 1.28. However, the finding in 8 studies that all OBX groups were above their controls was statistically significant (p<.004 - Wilcoxon's signed-ranks 120 test). Therefore, the average ratio was considered reliable; there was a real effect of OBX on PEI. The data for peripheral anosmia, the chemical destruction of the nasal mucosa, demonstrated no obvious difference from OBX treatments (138). The BIG ratios for olfactory peduncle oblation (r - 1.226) and peripheral anosmia (r - 1.373) were both statistically signifi- cant (p<.005). As no statistical test was made between the OBX and anosmic groups (they were separate experiments), and the ratios were close, no difference between the two treatments was assumed. No consistent pattern emerged regarding prior sexual experience or the age of treatment. Both significant and nonsignificant effects were reported for experienced and inexperienced males. As the inexperienced males were treated earlier (A - 6-80 days) in life than the experienced males (A - 125-240 days), the same conclusion must hold for the age of treatment. 5.20 The Effect of Blinding The removal of sight by enucleation resulted in a reduced PEI. 'The depression of the PEI was significant (p<.05) for PEII (89). The PEIZ had a larger difference between blind and intact males, but the difference was not significant for experienced males. The Blind/Intact ratios were rPEII - 0.897 and rm:12 - 0.873. As the ratios were very close, their average (r-0.885) was incorporated in the model for all PEIs. 121 5.21 The Effects of Penile Nerve Cuts (PNX) Severing and often sectioning one of the set of nerves innervating the penis and/or the pelvic region was one procedure for reducing or eliminating sensory information from the penile region. Larsson and S3dersten (142) removed a 5 mm bilateral section from the dorsal penile nerve close to the pubic symphysis. A significant increase in the PE11 was observed, although the change in actual PEI values was small. The Cut/Sham median ratio was r - 1.069. When the nerve cut and sham males were further treated to penile desensitization by the application of a topical anesthetic (Lidocaine), both male groups ceased ejaculation (142). Therefore, no PEI values were available, so the ratio, r - 0.0, must be assumed for penile anesthesia. The anesthesia obviously removed penile sensory information that the dorsal penile nerve cut did not. Vomachka (198) also severed the dorsal penile nerve, but unlike the previous study, he castrated all males and provided immediate hormone replacement (500 ug TP/rat/day). The nerve cut after hormone replacement reduced the number of males attaining ejaculation. Therefore, the changes in the PEI were based on only a few males. The average Cut/Sham PEII ratio over three repeated tests was r = 1.093 (n-6 pts.), and the average for PEIz was r - 0.998 (n-3). Neither of the differences were significant. A similar result was found in a second experiment (198) under three different hormone treatments. A cut and a sham group were treated with testosterone propionate (500 ug TP/day), fluoxymes- terone (500 ug FM/day), or the oil vehicle. Fewer males attained at 122 least one ejaculation than in the prior experiment, so the calculated ratios were less reliable (PNX groups generally had only 1 to 2 males attaining ejaculation). None of the PNX groups significantly differed from the shams. The average Cut/Sham ratio over 12 repeated tests at 4 day intervals for the three hormone groups were: rTP I 1.070 (nI12), rFM I 1.100 (nI4), and r011 I 1.001 (n=2) for PEIl. No data were available for PEIZ as PNX males never completed a second ejaculation. The ratios available for the calculation of a composite ratio, therefore, were r I 1.069 (142) and r I 1.093 plus r I 1.070, 1.100, & 1.001 (198). The average ratio, whether all were used or one ratio per experiment was used, became r I 1.07 for PEIl. As only one experiment reported a ratio (142) for PEIZ of r I 0.998, the r I 1.0 was incorporated by the model. The elimination of PEI due to the elimination of ejaculation was handled by the model values for the PEPIPM section. The PNX/Sham ratio of r I 1.07 was incorporated into the model, not because of statistical significance, but because every ratio was above 1.0. 5.22 Hormone Variable Introduction Each hormone treatment potentially has a time and a dosage variable. Castrated male rats are usually injected with a particular hormone or drug dosage once a day over a period of days. Changes in the behavioral measures develop over a number of days, dependent. on the hormone dosage. An alternative to injection delivery, infrequently utilized, is 123 the subcutaneous implantation of a silastic capsule containing crystalline or concentrated hormone. The implant releases hormone continuously over several days, while a daily injection is a periodic pulse. However, the implant dosage is difficult to determine. As the release of hormone from the silastic tube is a function of the surface area, the length of similar diameter tubing serves a relative measure of the dosage. Two alternative hormonal regimes are utilized. The maintenance regime initiates hormone treatments immediately after castration. The recovery regime begins hormonal treatments after the males' behavioral response has drapped to a near zero level (i.e., no intromission) well after castration. Frequently, the cessation of sexual behavior is assumed and hormone treatments are started at least two weeks after castration. The recovery of sexual activity is then observed with repeated testing under continuous hormone treatment. The different regimes are discriminated within the model by the DPC variable, the number of days between castration and the start of any treatment. The maintenance regime requires a DPC between 0 and 4 days and the recovery regime requires a DPC greater than 14 days. Hormonal treatments are categorized into five groups. The common gonadal hormone treatments are the first division. The treatments include castration, injection or implantation of various forms of testosterone, various estrogens, or both. The second division includes the injection of 13 different androgens, but not testosterone. A number of surgical treatments of the endocrine glands comprise the third; hypophysectomy, adrenalectomy, 124 throidectomy, and pinealectomy are alternatives. The fourth contains nongonadal hormones: LH, FSH, prolactin, ECG, or two forms of progesterone or pregnenolone. The final division deals with the injection of various anti-androgens, anti-estrogens, androgen mimetics, or aromatase enzyme inhibitor drugs. All but the mimetic are usually combined with a gonadal hormone, most frequently, testosterone. The division containing the most data is the gonadal hormone treatment group. 5.23 Gonadal Hormone Treatment Effects The Effect of Castration Castration resulted in a continual increase in the PEI over the days following castration until ejaculation ceased and the PEI was eliminated. The postcastration PEI was derived from the adjusted means of five studies using Long-Evans (58,59,198) and Sprague-Dawley (106,205) males. Testing occurred twice/week (59), once/week ($8,160,198), or once every two weeks (205). The maximum number of days with reported PEIs was 70 days, and only two studies (58,205) reported for more than 35 days postcastration. The response change after the cessation of testosterone (500 ug TP/day) maintenance (198) was used as a treatment analogous to castration. The PEI followed an accelerating pattern (Figure 5.6) until males failed to complete a PEI. The change in PEI was approximated by the equation: 125 .osHH a>mon m on Hmommm mosam> Hocoe one can Ahoazoa nosmmnmm nu.msm>muwcoq MVV oozed Spa: oopooccoo one hogan oameam m 509% meme .moddSpm oHanHm>< Seam mofiam 88.580888 Ham 323385 or» £0. 86.3 838.888 882 on... .8 838880 9m 32mg Aem 1.0 The equation line was fitted to two points, the Day 7 castration 131 ratio (rI1.444) and Day 10 (r I 1.0 at approx. CASTD I 10.) castration. Although the effect on the PEI has not been definitely substantiated, the increase in PEI parallelled the decay of the PEI response shown by low testosterone dosages after adult castration. As some debilitation due to early castration was reasonable, the equation was included in the model. Estrogen Treatments The PEI response to estrogen was minimal and often inconclusive. The only available studies reporting PEI values utilized a benzoate (EB) or diproprionate (EdP) form of estradiol. Treatment under both maintenance and recovery regimes was available.) The control groups were intact males, testosterone injected castrate males, or precastration tests for the experimental males. Effects under the recovery regime proved to be the more elusive. Five articles (11,164,176,l77,181) reported PEI data for 1 to 100 ug of EB injected for a period of 19 to 60 days, starting 31 to 70 days postcastration. The control males received 100 to 200 ug TP or 1000 ug T over the same treatment periods. No consistent relationship of dosage, strain, or period of treatment was observed. The EB/TTP ratios ranged from 1.079 to 1.291 (1 pt./experiment) for, presumably, PE11 (some studies did not specify the number of the PEI or the test length). The overall recovery ratio was r I 1.16. The ratio was considered reliable because all six points comprising the average were greater than 1.0. The deviations about the average ratio, 132 0.052 1:0.016 (nI6), were small. No indication was given of any effect occurring due to the length of treatment. Some effect on the PEI would be reasonable during the early stages of EB treatment, but data were not reported in that range. Bear in mind, the PEI values were from only responding males and frequently, many males did not attain the first ejaculation under EB treatment (see PE section). Only one study (176) reported more than one dosage of EB. Three dosages; 5, 50, and 200 ug/kg BW (approximately 2 - 80 ug/rat/day); were given for three weeks to intact males. No consistent dose response was evident. The mild elevation of PEI due to EB injection was within range of that of the castrate males similarly treated (r I 1.21 to 1.36). Because of the similarity in response between castrate and intact males, both were included in the overall model ratio (r I 1.16). The maintenance regime data was more explicable. Males were injected with 70 (59) or 150 (82) ug/day EB and 150 ug/day EdP (160) for 12 to 49 days, starting at castration. No consistent change from the intact (59,160) or 150 ug TP controls (82) occurred. Over the days of treatment, the PEI ratios fluctuated around the null ratio (rIl.0). The deviations from the null ratio were small (dev. I 0.073 1 0.017, nI14). No effect on the PET was assumed. Estradiol in either of its longer lasting forms had little or no effect on PEI in castrate and intact males. No change occurred under a maintenance regime, but some increase in PEI was seen under recovery. The recovery increase was statistically nonsignificant in the individual studies, but it was consistent over all studies. Any noticeable change in PEI due to estrogen treatment might have been 133 prevented by the frequent lack of ejaculation. 5.24 Androgen Effects Information was available on a variety of androgens utilizing both maintenance and recovery regimes. The effectiveness of an androgen induced PEI response was demonstrated by comparison with the PEI induced by the testosterone (T or TP) control in castrate rats. The minor androgens included: dihydrotestosterone (DHT), androstene- diol (Aeol), androstenedione (Aeone), l9-hydroxyandrostenedione (HAeone), 30b and BB-androstanediol (Aaol), androstenedione (Aaone), and l9-hydroxytestosterone (HTP). Combinations of EB and testoster- one with DHT and other androgens has been reported, also. Dihydrotestosterone (DHT) Dihydrotestosterone has been utilized in both its free (DHT) and propionate (DHTP) forms under both maintenance and recovery regimes. The PEI data using a recovery regime was, however, more scanty. Three studies (12,164,177) reported data using recovery conditions. However, the reported PEI values were averages for the entire experiments, so changes over repeated days of DHT treatment could not be established. Free DHT was injected in 0.5 (177) and 1.0 (164) mg dosages, and DHTP was injected in a 200 ug dosage. The castrate males were injected for 26 to 36 days after a wait of 42 or 70 days after castration. All males were sexually experienced. The DHT(P)/TP recovery ratios fell both above and below the 134' r I 1.0 value, and at least one ratio was statistically significant in either direction. The bidirectionality of the PEI effect presented a difficulty because the model required a single effect ratio; there was no basis for differentiating a significant rise from a significant fall in PEI based on the DHT(P) treatment procedures. No consistent differences existed for sexual experience, duration of injection, time postcastration, or the number of the PEI (all were for PEIl). The only experimental difference was found for the time between sex tests. The two high ratios (r I 2.034 (12) & 2.075 (177)) were tested at two (12) and three (177) day intervals, while the low ratio (r I 0.693) had weekly treatment (TBT-7) intervals (164). However, as the males were tested to only the end of PEIl, a test interval (TBT) effect was questionable. Remember, the effects on PEI due to TBT occurred for tests to sexual satiety. The bipolar effect may well have been due to some property of the PEI, as yet unknown, or simply an experimental artifact - although a significant one. As the cauSe of the bipolar DHT(P) effect were in contest and the other model values were averaged ratios, the DHT(P) ratios were also averaged. The resulting average was r I 1.60. Consequently, the deviations (0.586 110.191, nI3) from the calculated ratio were large. Unlike the recovery data, maintenance data presented a range of points over the treatment period. Five studies (159,160,161,l63,205) provided data on sexually experienced males over days of treatment. Four of the studies (159,160,161,l63) emerged from Parrott's laboratory, so internal consistency existed for much of the data. 135 The Parrott data provided no evidence of differences from 75 to 200 ug of DHT(P). Similarly, no differences due to strain (Wistar (159, 161,163) vs. Sprague-Dawley (160)) were observed. The study average ratios ranged from 1.607 to 1.747. The remaining study (205) utilized Sprague-Dawleys injected with 800 ug DHT, and its average ratio was r I 1.590, sufficiently close to the other ratios to be equivalent. No consistent changes in the PEI were seen over the treatment periods of 21 to 70 days of injection for tests given at weekly (159, 160,161,163) intervals or every two weeks (205). The average of all studies, r I 1.66, was assumed for all DHT(P) maintenance treatments. The lack of change over days of injection was demonstrated by the deviations from the model ratio of 1.66. The means and standard errors of the deviations were generated for each week of treatment, producing six deviation groupings. The range of means was 0.148 to 0.337 and the standard errors ranged from 0.029 to 0.168. Neither the high nor the low endpoint of the ranges fell at the beginning or end of testing. Although no change was seen after 7 days of treatment, nothing was reported regarding the first few days of treatment . The PEI average ratios attained under both the recovery and the maintenance regimes were essentially equivalent, r I 1.60 under recov- ery and r I 1.66 under maintenance. As far more data were available to support the maintenance ratio, 1.66 was the assumed ratio for the model for both regimes. The PEI ratio response to DHT(P) was assumed for both sexually experienced and inexperienced males. 136 The Combination of Estrogen with DHT(P) Effective dosages of EB and DHT(P) produced results equivalent to TP treated males. The production of a normal PEI response occurred under both recovery and maintenance regimes. The injection _ of 2 ug EB with 200 ug DHTP at 31 days postcastration (11) produced the same PEIs as 200 ug TP. Larsson, Sgdersten, and Beyer (144) demonstrated a dose response for 0.05 to 50 ug EB given in conjunction with 1.0 mg of DHT at 50 days postcastration. The PEI approximated that of the intact male with the 0.5 ug EB or more combinations. At lower dosages, the response followed a linear relation: Larsson st 31. (145) combined 500 ug DHT with 1 and 5 ug of free estradiol (E2) or estrone (E1). No PEI differences were found between the two estrogens with DHT or between the two estrogen dos- ages. However, TP control values were not presented. No differences from TP castrate or intact males was assumed, because the E1 or E2 + DHT PEI values were within the range of PEI controls reported in other Larsson studies using the same strain (144,177,181) one year prior. The same lack of effect was observed with 100 ug of EdP and 100 ug DHTP when treatment began at castration (163). Therefore, the combination of estrogen with DHT(P) in castrate males did not affect the intact PEI level response until the dosage of estrogen fell below 0.5 ug. This held for both the recovery and maintenance regimes. 137 Combination of Testosterone with DHT(P) The addition of testosterone washed out any effect of DHT(P) on the PEI. After 25 or more days treatment postcastration, 200 ug DHTP with 4 ug TP (11) or 500 ug DHT with 200 ug TP (177) provided no PEI changes from TP alone. The same lack of change occurred for 21 days pretreatment with 1 mg I before the addition of 1 mg DHT (141). Similarly, treatment at castration produced no PEI change. DHTP and TP at 100 ug (163) or 75 ug of DHTP plus 150 ug of the synthetic androgen, 19-Nortestosterone, showed no change from TP or intact controls over 21 or 35 days of treatment. Androsterone (And) PEI maintenance data appeared in only one study (160) of androsterone. Androsterone propionate (150 ug) showed no change from castrate PE11 over five weekly tests. The And/cast. ratio was assumed to be 1.0. The overall And/intact ratio was r I 1.59 (nI5). Unfortunately, no data were available for higher dosages. Androstenediol (Aeol) The same researchers (46,157), using different strains, reported data on androstenediol. Inexperienced males were treated at 60 to 120 days postcastration. The earlier study (46) reported no effect on PE11 with 1000 ug Aeol compared to the same dose of I over 33 days of injection. The latter study (157) could report no PEI values 138 for 0.3 and 1.0 mg of Aeol because only one male attained ejacula- tion. No effect was found for PEIl at the 3.0 mg dosage. The Aeol/T ratios fell both above and below the 1.0 value. No explanation of the differing responsiveness to the 1.0 mg Aeol dose was given nor was one readily apparent. No effect on the PEI was assumed for the model. Androstenedione (Aeone) The PEIl was reported unchanged (46,157) and significantly increased (164) by 1.0 mg Androstenedione under recovery conditions, when compared with the same dosage of T. The average Aeone/T ratio for studies (46,164) with a sufficient number of responding males was r I 1.49. Unfortunately, no time course was given under recovery conditions. No effect was found for the PE11 under a maintenance regime over five weekly tests with 150 ug of androstenedione enolpropionate (160) and over five tests every two weeks with 800 ug Aeone (205). The controls were respectively intact males and males given 800 ug TP. The deviations about the assumed 1.0 ratio were minimal (0.054 :_ 0.014, nIlO). Apparently, dosages of at least 150 ug Aeone were sufficient to maintain at least the first PEI at normal intact levels in those males attaining ejaculation. However, waits of 1.5 months or more after castration required Aeone dosages greater than 1.0 mg to return the PEI to near normal levels. 139 Hydroxyandrostenedione (HAeone) The PEI effects of l9-hydroxyandrostenedione did not match those of androstenedione under maintenance conditions. Parrott (160) showed an elevation in PEI in the 150 ug HAeone group, that did not occur in the same dose Aeone group. The average HAeone/intact ratio over five weekly tests was r I 1.26 (nI5). No evident pattern of increase over the time of treatment existed. Apparently, the PEIl rise must have occurred prior to the first test at 7 days with injection. The PEI response for Haeone stood between that for intact or TP controls and for castrates given oil; the ratios were closer to the intact than the castrate. The response to HAeone was more variable than for Aeone. The deviations from r I 1.26 were 0.120 i:0.049 (nI5), while those for Aeone were 0.054 t 0.014 (nIlO). A larger variation would be expected as the PEI response deviated from the normal level as the behavior started to decay, indicated by the reduction in the number of males attaining ejaculation (see PE section). The model assumed r I 1.26 for all HAeone treatments. Androstanediol (Aaol) The two isomers, 3dr and 38-androstanediol, affect the PEI similarly. After treatment of 150 ug Aaol at castration (160), the rate of response was extended in time. However, the 3OPA801 had the stronger effect. The 38-Aaol had no obvious androgen properties; the PEI was not significantly different from castration alone. The 140 deviations of the 3a-Aaol/Cast ratio were high (0.283 :;0.193, nI3) due to the rapid decay of the PEI. The PEI decay with 3ahAaol was less rapid; the Aaol/Intact ratio was approximated by the equation: rPEI I 0.0123‘AAAOLDI + 1.62 The equation established a ratio value of r I 1.706 for the first weekly test (AAAOLDII7). The PEI ratio rose linearly to the final value of r I 2.05 by the last test at 35 days (AAAOLDII35). The deviations about the line were 0.114 110.041 (nI5). The high ratio value at the first test (AAAOLDII7) indicated the PEI was approaching that of the castrate male; the PEI.decay was well established. However, note that the PEI was maintained for two weeks longer by the 30 form. The addition of DHT to Aaol had no synergistic effects on the PEI. The addition of 1.0 mg 38-Aaol to 200 ug DHTP (12) at 42 days postcastration for 26 days of injection showed a significant rise in the PEI, approximating that of DHTP alone. Although the PEIl rise was higher with DHTP alone, it was not significantly more than for the two androgens combined. As nothing was changed within the model by 38-Aaol, the values for DHT(P) alone would be reported. Androstanedione (Aaone) Androstanedione enol propionate helped maintain the PEI when injected in 150 ug doses starting at castration (160). However, the PEIl still tended to increase over the period of treatment, so Aaone was not fully effective. The rise in the Aaone/intact ratios 141 for PEII was linear: rPEI I 0.0125'AAONEDI + 1.0 ; when rPEI > 1.0 The rise was slow and began at intact levels (rI1.0). The PEI values might plateau beyond the 35 days of treatment reported in this study, or it might continue to rise to the castrate level with prolonged treatment. Neither possibility was demonstrated, but for the model the ratio was allowed to continue the rise with prolonged treatment, because some PEI decay was indicated by the decreasing number of males ejaculating over the course of treatment. l9-Hydroxytestosterone (HTP) The PEI was maintained by 150 ug of l9-hydroxytestosterone (159). No consistent change from the 1.0 ratio (HTP/intact) occurred on three tests during 35 days of injection. The small deviation (0.065 1:0.013, nI6) from 1.0 indicated a very stable relationship. When 100 ug of HTP and 100 ug of DHTP were given in conjunction, the effectiveness of the HTP was reduced (163). The HTP+DHTP/intact ratio rose from r I 1.0 to r I 1.176 (nI3). The overall ratio for 200 ug DHTP from the same study was r I 1.745 (nI3). The effectiveness of either androgen in maintaining the PEI tended to average when comr bined, providing a ratio between the independently treated androgens, indicative of a competitive rather than an additive or synergistic effect. The increased PEI was stable over time, as indicated by the low deviations (0.066 :_0.031, nI3). 142 Androgen Summary The comparative effectiveness of the various androgens was best seen under the same treatment conditions. Parrott (159,160,163) had reported sufficient data under a maintenance regime at dosages approximating 150 ug to make solid comparison possible. The PEI for intact or TP treated castrates served as the baseline (r I 1.0). The normal castrate PEI rose exponentially from the day of castration onward. The effectiveness of any androgen in maintaining the PEI was demonstrated by its ability to retard the PEI rise postcastration or to prevent the rise completely, remaining at intact levels. Androstenedione and HTP, as well as androstenediol, were effective in keeping PEIs at intact or TP castrate levels (46,157). Androstanedione and l9-hydroxyandrostenedione were less effective. Higher PEI rises were seen with DHT and 3a-androstanediol; even though PEIs rose to a high level with these two androgens, the response was maintained longer than occurred for castrates. The ineffective androgens, having PEIs equivalent to castration alone, were androsterone and 38-androstanediol. Unfortunately, little was known of how the androgens would perform under recovery conditions. The DHT(P) data indicated the PEI response would attain very similar levels in either regime. Therefore, the androgens of high and medium effectiveness might potentially produce the same level of PEI response under recovery when given for prolonged periods. 143 5.25 Endocrine Glands - Adrenalectomy Removal of the adrenal glands from intact males did not affect the duration of the PEI (48). Over 7 repeated tests to 20 days following adrenalectomy, no significant alteration of the PEI was seen. The same lack of effect of adrenalectomy was seen in castrate males given increasing doses of TP (7-28 ug/100 g BW) using a recov- ery regime (48)(r I 0.989) or given 150 ug TP using a maintenance regime (82)(r I 1.008 & 0.819). The lack of effect was also assumed for castrate males given 150 ug EB (82)(r I 1.157). Block and Davidson (48) did report a drop in PEI in adrenalec- tomized and castrate males compared with castrate males, but the drop was nonsignificant (r I 0.781). The drop was highly questionable as the number of males attaining ejaculation decreased rapidly following castration. However, because the lack of overlap of the standard errors and means between the two groups indicated an actual effect might have existed, the combination of castration and adrenalectomy was given a PEI ratio of r I 0.80 within the model. 5.26 Drug Effects Several drug groupings were provided with PEI data. Fluoxy- mesterone was an androgen analog, the anti-androgens were represented by cyproterone acetate and flutamide, and the anti-estrogens were represented by HER-25, Eigfclomiphene, and ICI-46474. The drugs inhibiting the aromatase conversion of testosterone to estradiol were metopirone and aminoglutethimide. All anti-androgens, anti-estrogens, 144 and aromatase inhibitors were tested in combination with injection dosages of testosterone sufficient to maintain sexual behavior at normal intact level in castrate males. The effectiveness of the inhibitory drugs was determined by the comparison of the drug plus T treated groups with those given T but not the drug. Fluoxymesterone was injected alone and compared against a separate testosterone group. Fluoxymesterone (FM) Vomachka (198) provided the only data on the effect of FM on the PEI. All treatment groups were previously maintained on 500 ug TP. The males were either in a penile nerve cut group or a sham group that had been repeatedly tested prior to the start of the 500 ug FM treatment. After the maintenance TP was stopped and the FM started, the PEI values increased compared with the same dosage TP control group. The increase in the FM/TP ratio continued until approximately 35 to 40 days of treatment, where the PEI ratio steadied about r I 1.60 until the final test at 56 to 57 days of injection. The change over days of treatment was fitted to a sigmoid curve with a midpoint at 21 days of injection. r I 0.60° 1 PEI /(1 + (21/DYFM)4'5) + 1‘0 The equation-curve started at r I 1.0 at the start of treatment (DYFMIO), accelerated up to 1.30 by 21 days treatment (DIEM-21), and decelerated approaching the maximum ratio of 1.60. The rate of change was controlled by the exponent (4.5). The rise in PEII 145 values was very similar in pattern to the rise with oil treatment, that followed the PEI rise seen for castration. However, after the initial rise, the oil treated males could not maintain the PEI even at the higher level. Only one male had a demonstrable PE11 by 21 days of oil injection. The PM males continued to demonstrate PEI responses in the majority of the group (nI8) to the end of testing (DYFMI56). The FM/TP ratios for the penile nerve cut (PNX) males also increased, but no consistent pattern was discernible. The FM-PNX ratios varied about the average r I 1.27 (dev. I 0.139 1:0.037, nI5). Furthermore, PEIs terminated by the seventh test (DYFMI35). The deviations from the model ratios for the FM sham group were similar to those for the FM-PNX group. The sham deviations were 0.145 110.048 (nIlO). However, the sham deviations were separable into those on either side of 21 days of treatment; the variation was greater after 21 days (0.238 :;0.077, nI5) than up to 21 days (0.052 t 0.012, nI5). The higher variation about the model ratios during the earlier days of treatment indicated the PNX group PEI response was showing signs of decay much earlier than the sham group. The PEI decay started later for the FM sham males as indicated by the higher varia- tion after 21 days of injection, as well as, the higher FM/TP ratio. With consecutive PEIs, the response to FM differed. No rise in PE12 values occurred in the FM sham males; no FM-PNX males were responding by PEIZ. The FM/TP sham ratios fluctuated about r I 1.0, unlike the sigmoid rise that occurred for PEII. The deviations (0.149 :;0.041, nI7) for PEIZ were in the same range as for PEIl, so the lack of change during PEIZ was not due to the vagaries of wild fluctuations. However, the small number of males responding on 146 the PEIZ (nIl-3 males) may have been a contributing factor. To reiterate, FM treatment resulted in a rise in the PEIl, but not the PEIZ, following a sigmoid curve paralleled at a higher FM/TP ratio by the FM-PNX males, but for only a short duration of treatment. The rise was very similar to that for castrate males, but the FM maintained P811 and PEIZ responses far longer than oil controls that approximated castration. The concept of behavioral decay was well demonstrated by the PEI response to FM. Decay implied a gradual degenerative change in response rather than the presence or absence of response indicative of a threshold. As the cessation of ejaculation approached, the PEIl became more variable, as well as increasing compared to the control. For sham FM males the initial PEI rise showed little variation, but later during the plateau phase, the variation was much greater, at the same time as the number of males responding in the group was slowly decreasing. The FM-PNX group demonstrated its decay earlier with an immediately higher ratio and high variation. The sham FM PEIZ response was of higher variation earlier in treatment, and the response disappeared earlier. However, the lack of change in PM PEIZ did not follow previous patterns of parallel effects across the consecutive PEIs. To completely fit the decay ideal, the PEIZ should have shown an increased ratio along with its higher variation. Cyproterone Acetate (CYA) The injection of 10 mg of the anti-androgen, cyproterone acetate, into intact (49) or TP (100 ug (49) or 150 ug (204)) treated 147 males produced no change in the PEI. The TP+CYA/TP ratios ranged from r I 0.807 to r I 1.132, all statistically nonsignificant. Only in castrated males did CYA have an effect. CYA reduced the postcastration rise in the PEI (49). The ratio (CAST+CYA/CAST) was r I 0.724, and the difference was statistically significant. The castrate males given CYA were nearly equivalent to castrate males given TP (r I 0.977), a definite indication of some androgenic or estrogenic effect of the CYA alone. Unfortunately, the time course of the effect for castrates was not available; only an average values was given for each treatment group. The model reported no change for CYA in conjunction with testosterone, but did return the r I 0.72 alteration of the castration pattern. Flutamide (FL) Like CYA, the anti-androgen, flutamide, had a notable lack of effect on the PEI. When FL was injected (25 or 50 mg/kg BW) into intact, castrated or 100 ug TP treated castrate males (180), no altera- tion from their like controls occurred. Under a recovery regime, the sexually experienced males had E/C ratios ranging from r I 0.938 to r I 1.085. Flutamide, a nonsteroidal androgen, did not show any andro- genic or estrogenic effects in castrate males, as occurred with CYA. HER-25 The first anti-estrogen under consideration, HER-25, was given in conjunction with 1.0 mg T. Beyer at 31. (47) treated inexperienced 148 males under recovery conditions (DPCI60) with 2, 8 or 28 mg of MER-ZS. No changes in the PEIl were found for any dosage, compared with the T controls. MER¥TIT ratios ranged from r I 0.948 to r I 1.034. When 10 mg MERIZS was given in conjunction with DHTP (200 ug), to experienced males, again, no effect was found (12) when compared to DHTP alone (MER+DHTP/DHTP I 1.144). In addition, both the DHTP and the MER.+ DHTP groups were significantly different from the 200 ug TP control group. cis-Clomiphene (CLOM) Like HER-25, cigfclomiphene was ineffective in significantly altering the PEIl when given with T. Beyer stflal. (47) gave 0.25 and 1.0 mg of CLOM under recovery conditions over a 21 day period. The CLOM/T ratios were r I 0.916 and 1.066 for the low and high dosage of CLOM, respectively. ICI-46474 The final anti-estrogen under consideration, ICI-46474, was no more effective in altering the PEI than the others (47). The ICI+TIT ratios for dosages of 0.1 or 0.3 mg/kg BW (approximately 0.04 8 0.12 mg/rat) were r I 0.975 and r I 0.966, respectively. ICI deviated from the previous anti-estrogens in eliminating ejaculations with the highest dosage of 1.0 mg/kg BW (0.40 mg/rat). Any PEI changes were thus truncated. PEI did not appear to change up to the point of the 149 elimination of ejaculation. Metapirone (MET) Beyer 55.2}! (47) also studied aromatase inhibitors. Metopirone was given every 12 hours for 96 hours starting one hour before the single injection of 6 mg TP. A MET dose response was indicated for the PEII, although the largest change was not statistically significant. The MET+TP/TP ratio rose from r I 1.042 at 10 mg MET to r I 1.433 with 22 mg MET. Under most conditions a ratio of 1.43 would be significant, but as the number of males responding (4/10) was small, the PEI values did not attain statistical significance. The model in- , eluded a linear dose response for MET, as the one high ratio was suffi- rPEI I 0.036'DMET + 0.64 ; when rPEI 2- 1.0 ciently compelling, especially since the increase with increasing dosage was in the expected direction for an interference with the action of TP. Aminoglutethimide (AGT) The effect of the aromatase inhibitor, aminoglutethimide, was a major one, but irrelevant to PEI. Dosages of 5.0 and 15.0 mg of AGT combined with the one injection of 6 mg TP (47) completely eliminated ejaculation. The elucidation of any PEI effects was thereby blocked. To demonstrate any potential effects on the PEI, lower dosages would have been required. 150 _Drug Effects Summary The androgen analogue, fluoxymesterone, was partially effective in maintaining the PEI in castrated males after the removal of TP maintenance. The PEI was not maintained at normal levels, but the behavior was sustained longer than the equivalent of castration. As FM was proposed to act as a peripheral androgen, the extension of the PEI was likely due to the maintenance of penile sensitivity. This was corroborated by the more variable, short effect of FM on the PEI in penile cut males. The FM-PNX males approximated the castrates. Neither of the anti-androgens, CYA or FL, altered the PEI response of males given systemic testosterone. The lack of effect was unlikely due to insufficient dosage as 10 to 25 mg was substan- tial, and the dosage of TP was reasonably low (100-150 ug). However, CYA did inhibit the increase in PEIs following castration, somewhat. CYA undoubtedly had some androgen properties. The anti-estrogens; MERI25, gigfclomiphene, and ICI; were all unable to alter the PEI. However, the PEI duration did not show the decay that occurred with castration, the minor androgens, or FM. The PEI did not rise before it was eliminated by the failure to ejaculate. The aromatase inhibitors were most effective in interfering with testosterone maintenance. MetOpirone caused an increase in the PEI usually seen as the PEI decayed. AGT was effective in eliminating the PEI because it eliminated ejaculation. Any alterations of PEIs at lower AGT dosages was unknown. The aromatase inhibitors were given in conjunction with an unusual testosterone treatment, a single injection at high dosage (6 mg). The procedure may have made the 151 drugs appear more effective than they would under repeated injections of a lower dose of TP. 5.27 PEI Composite The postejaculatory interval was a stable measure of sexual behavior. Its stability was demonstrated in its resistance to change from normal durations and in its patterned changes with treatment, when change did occur. The PEI E/C ratios changed less than other behavioral measures due to both the large numerical size when expressed in seconds and the low inherent variability of the PEI. The PEIs resistance to change was expressed in the number of experimental treatments failing to produce any consistent alteration. the majority of treatments (55.4% - see Appendix C) showed no change. the remainder showed either an increase (33.72) or a decrease.(12.0%) from normal PEI durations. Almost all of the experimental treatments referred to PEII alone, as the first PEI was usually the only one of the five consecutive PEIs reported in the literature. However, consistent effects on consecutive PEIs were demon- strated in variables determining normal behavior. These included the intrinsic variables (e.g., Age, Strain, or TDN) and independent experimental variables (e.g., TBT, sexual experience, raising condition). Within all these variables, the experimental PEIs and control PEIs showed parallel increases with consecutive PEIs. The PEIs for young and old males, although higher than normal adult males, had parallel age patterns from one consecutive PEI to another. The parallel increases were also seen for the comparison of 152 day and night testing times. No effect on the PEI was seen for sexual experience or raising condition. Finally, the increase in PEI due to the decreasing time between tests (TBT) was similar between PEIl and PEIZ. Where changes in the PEI were demonstrated, the direction of change was related to the type of treatment. As the value of the experimental variable moved outside the ”normal” range, PEIs tended to increase in relation to the distance removed from the "normal". As the age of the test males diverged from the adult range (145-450 days), the PEI increased; the PEI increase was exponential with approach to puberty and with increasing old age, the increase was linear. When the hour of testing (TDN) diverged from 5 hours into the dark phase or occurred in the light phase, the PEI increased. Similarly, forcing fewer days between each test lengthened the PEI. Mild experimental stimulation tended to decrease the PEI. Enforcing an interval between intromission(s), replacement of the original test female with a new one at satiety (no effects at each E), mild electric shock, and conditioning to attain access to the female, produced a decreased PEI. However, more drastic or potentially debilitating treatments, such as electroconvulsive shock, conditioning to noxious stimuli (e.g., a loud bell) proved to increase the PEI. The same held for the removal of sensory input. Olfactory bulbectomy or peripheral anosmia and sectioning of penile nerves increased the PEI. The exception was the statistically nonsignificant decrease due to blinding. In all cases where a hormonal treatment effect was evident, the 153 PEI was increased. Castration, the injection of low dosages of testosterone or estradiol, or any repbrted dosage of DHT(P) produced increased PEIs. The postcastration exponential rise was the most prominent and served as one base of comparison for other hormones. Several lesser androgens also produced increased PEIs, varying from the more effective androstanedione, producing the least change from intact PEIs, to androgens (And & 38-Aaol) approximating the castration increase. The PEI response to many hormonal treatments had the appearance of a decay phenomenon. The changes due to the time of treatment, lower dosages, or comparison of the effectiveness of similar hormones at the same dosage were to increase the PEI and increase the variability in the male group PEI average reported. A decay process does have the same characteristics of increasing variability and deviation from the "normal" state. The changes in PEI over the days of hormone injection deve10ped gradually and appeared as males within the treatment group ceased ejaculation. The PEIs tended to increase as did the variation in PEI values until the PEI measure dropped out completely with the cessation of ejaculation in all males. Of course, the later successional PEIs dropped out before the PEIl. Perhaps, the lack of change of PEIs following PEIl, when changes did occur in the PEIl, was due to the elimination of later ejacula- tions before any decay effects could be seen. This indicated the possibility that the mechanisms controlling PEI were more resistant to hormonal deficiencies than those controlling ejaculation. The presence of a noticeable PEI decay effect was related to the degree of peripheral maintenance of penile structure. Castration 154 provided a clear example. Immediately following castration, testosterone blood levels fell rapidly to nondetectable levels by one to two days (see Testosterone section). However, influence of the prior T continued longer at the penis; the penile papillae, important for sensory stimulation, did not start to regress until about six and one-half days after castration. The papillae approached the regres- sed state of long-term castration by 8 to 10 days after castration. Under these conditions following castration, the decay of the PEI was pronounced. The PEI decay was also noticeable for the androgens other than T, especially in the case of DHT. When DHT(P) was administered at castration, the PEI rose to a plateau level (r I 1.66) long before the cessation of ejaculation. DHT maintained PEIs at the higher levels for up to 70 days of daily injections. Admittedly, the decrease in ejaculating males was similar between oil and DHT(P) castrates, but DHT(P) did sustain PEI decay effects far longer, probably due to DHT's known ability to completely maintain the penile structure and consequent sensation. Other systemic androgens allowed the rise in PEI similar to DHT and castration, but to varying degrees. Administration of 3GPA801 resulted in a PEI rise (r I 2.02) over 35 days of injection. Aaone and HAeone also allowed some PEI rise (r I 1.30), that remained relatively stable from 14 to 35 days of injection starting at castration. Other androgens approximated either the response of castration alone (38-Aaol, And) or intact males (Aeone, HTP). The greatest PEI decay was demonstrated with fluoxymesterone (FM), a synthetic androgen believed to act only peripherally. As 155 described previously, FM maintenance treatment initially resulted in a rise similar to castration, but the PEI was maintained to the end of testing (57 days of injection) at a high level (r I 1.60). In addition, FM treatment demonstrated a clear increase in PEI variability with the prolonged treatment. Both elements of decay were clearly in evidence and again tied to the maintenance of penile sensitivity. Essentially, PEI decay was observed only when ejaculations were at least temporarily prolonged through peripheral penile stimulation. Hart (92,94) demonstrated that the mechanics of ejaculation were controlled in the lower spinal areas; the ejaculation reflexes remained in spinally transected males. The reflexes were maintained by testosterone and DHT in castrated males. T, DHT, and FM also maintained the penile papillae (see PP and PW section). Furthermore, PEI change due to sensory manipulations occurred. only when not related directly to the control of ejaculation. OBX caused PEI increases, although blinding did not, but neither eliminated ejaculation. However, penile nerve cuts did more to eliminate ejaculation than to stimulate PEI change.' PNX caused little PEI change (r I 1.07) in intact and TP castrate males, and in FM-PNX.males, ejaculation rapidly disappeared; the PNXIFM/TP ratios did not rise to the level of the sham FM males. Similarly, penile anesthesia resulted in no ejaculation and observable PEI decay, but ejaculation was the prerequisite. Hormonal effects on the PEI outside those of the gonadal and androgen hormones were scanty. Adrenalectomy had no effect on intact or TP treated males and only questionable effects when combined with 156 castration. No data were available for the group of nongonadal hormones or other manipulations of the endocrine glands. Similarly, little was added to the PEI picture by the treatment with anti-androgens, anti-estrogens or aromatase inhibitors. None of the anti-androgens or anti-estrogens produced any significant changes in the PEI. These drugs may have been more effective in eliminating ejaculation than allowing PEI decay effects to appear, or they were just ineffective. The aromatase inhibitors blocked the testosterone conversion to estrogen, but did not block the conversion to DHT, that would suggest continuance of peripheral sensitivity important for PEI decay. unfortunately, metopirone had no effect on ejaculation, and the increase in the PEI at the highest dosage (22 mg) was nonsignificant (r I 1.43). AGT was highly effective in eliminating sexual behavior at the dosages utilized, but'with no ejaculation, PEI changes were impossible. At lower AGT doses (<5 mg), some interesting PEI effects might have been seen. The aromatase inhibitor data were further complicated by the use of a single dose of testosterone. It was unfortunate that the inhibitors were not used to best advantage, as they might well have added further support to the need for peripheral maintenance of ejaculation necessary for the demonstration of PEI decay. Chapter 6 A Summarization of the Input - Output Variable Relationships 6.1 Introduction The previous chapter on the PEI measure provided a detailed look at the effects on PEI due to the input variables. The representation of the effects on the PEI by the model values and equations were also discussed. The PEI measure provided an adequate example of the nature of the model and all the subprograms for the output variables. Because a complete discussion of each of the output variables would be exceedingly long, the effects on each of the remaining output variables were summarized. This chapter provides a summary for each input variable, excluding the PEI. Each behavioral, penile, and hormonal measure has a separate section. Although the discussion of the remaining output variables is curtailed, the details of the calculation of effects of the model and their representation within the model are equivalent to those for the PEI. Appendix 0 provides a listing of the direction of effects upon each of the behavioral measures, as well as any lack of effect. The behavioral measures; IL,IF,EL,EF,PE,PI,PM; are described first. 157 ' 158 6.2 Intromission Latency (IL) The intromission latency is the first duration measure en- countered in the sexual behavior sequence, with the exception of the mount latency that was data poor. The intromission latency (IL) is defined as the time (in sec.) from the introduction of the female to the test arena to the occurrence of the first intromission. Only one IL occurs during a sexual behavior test, regardless of the number of ejaculatory series. An exception is sometimes made for treatments where the female is removed from the arena and later replaced during the ongoing behavior, as occurs for an enforced interval between intromissions (EICI) or during the PEI (EPEI). These "intromission latencies" after the female is replaced are not comparable to the IL at the start of testing. Therefore, any IL values appearing in the model for ejaculatory series other than the first series are these pseudo-1L8. A further exception should be mentioned. When no data were reported for the IL, but the less reported mount latency (ML) was reported, for a particular treatment variable, the E/C ratios for the ML were utilized as a replacement for the IL. Intrinsic Variables The extremes of the intrinsic variables tended to increase the IL length. The IL was longer at the younger (140,178) and older (119,132,140) ages, with no significant changes during the adult ages (213-426 days). The increase in IL was exponential as the age diverged from the adult range. Sexual testing during the light phase 159 of a 24 hour light cycle resulted in a nonsignificant increase (31) in the IL. During the dark phase, the IL was longest near lights-out and shortest near lights-on (63). The linear decrease with increas- ing TDN (hrs. during day) was nonsignificant. With decreasing number of days between testing, the IL exponentially rose to a maximum E/C ratio of 19.0 at TBT-l (30,76). The lack of prior sexual experience also resulted in increased ILs; differences were both statistically significant (64,70,169) and nonsignificant (48,159,169). However, raising a male alone (Isol.)(22,87,184) or with females (Cohab.)(70,184) decreased the IL when compared with males raised with other males (Seg.). The isolate IL was the most affected. The cohabitation condition interacted with the sexual experience variable, as the IL increased with reduced sexual experience. Due to the experience alone the cohabitant males would be expected to show a lower IL than the segregate males. However, there was no obvious explanation for the reduction in the IL of the isolate males. When the experimental male was raised with females, but separated from them by a double wire mesh (SCREEN), these males were comparable to the segregate males (184). Behavioral and Stimulus Variables The behavioral treatments demonstrated no consistent pattern of effect. The latencies to intromission, the pseudo-IL ("IL"), re- ported for enforced intervals between intromissions (EICI) in- creased with lengthening intervals (39). However, the "IL" 160 initially fell gradually to a nadir from approximately 1 to 8 minute EICIs (91,130). Although no support was available, the "IL" would be expected to gradually increase with longer EICIs until reaching the level of a normal IL. The number of intromissions allowed prior to an EICI was an additional factor; the more intromissions allowed before the EICI, the greater was the "IL" decrease (39). For the enforced PEIs, the "IL” decreased to E/C r I 0.24 (39,68,126) and started to increase with EPEIs longer than 150 minutes (39). The replacement of the current stimulus female with a different female (NFRESH) resulted in differing effects on the ”IL” at replacement. No change occurred when the original female was replaced with a fresh female after an ejaculation (68). On the other hand, the ”IL” increased when replacement was made after the attainment of sexual satiety (44,56). No interaction (44) existed with a EPEI and treatment at satiety. Electric shock stimulation during testing usually resulted in a decrease in the IL (23,51,52,81,l7l,173). However, if the level of shock were further increased, the IL increased. The increased shock level was either an intensity change, 100 up to 380 volts (23), or a frequency change, one to ten shocks per minute (52). When a bar press paradigm for access to a female was added to the lower shock condition, the effect of shock was eliminated (173). The stronger effect was the bar press, which increased the IL, washing out any shock effect. Electroconvulsive shock significantly increased the IL washing out any shock effect. Electroconvulsive shock significantly increased the IL during 12 days of daily treatments (26). Unlike the increase due to the positively reinforcing bar press 161‘ paradigm, the IL decreased under a negative reinforcement paradigm, if any change occurred (24,208). The negative reinforcement was a shock given when the male approached the stimulus female. However, if the conditioned males were tested without shock in a novel arena, the effect disappeared (24,208). Apparently, the effect of shock became situational. The conditioning Shock and the shock given to stimulate performance both decreased the IL when testing occurred in the same apparatus as the shock. This conditioning effect, therefore, was confounded between the conditioning and shock stimulus. The primary effect was probably that of shock; the males learned to anticipate the shock in a specific environment, and performed commensurately even when shock was not presented. Several other stimuli produced differing effects. The fitting of a large collar (96), preventing genital grooming, decreased the IL. Handling the males during testing (132) produced no change in IL in younger males (5-6 mos.), but did produce a nonsignificant increase in the older males (20-25 mos.). When the experimental male was exposed to a capulating pair prior to testing (90), a nonsignificant decrease in the IL occurred, but copulation with a female with a closed vagina (VagX) resulted in no change (88). Sensory Variables The sensory manipulations consistently resulted in an increased IL, provided an effect did occur. The removal of the olfactory bulbs (OBX) and surrounding brain areas or peripheral anosmia induced a 162 questionable increase in the IL. Different studies reported statistically significant increases (45,98,206) and decreases (137), as well as, nonsignificant increases (45,138) and decreases (14,100,168). The overall average was r I 1.76, and because the significant increases were more numerous, the average was adopted. OBX certainly created highly disrupted sexual behavior, because many of the-OBX males did not display the behavior (see PEPIPM section). Blinding altered the IL only in inexperienced males (84,85). Blind males with some prior sexual experience provided just nonsignificant changes (14,89). Severing nerves innervating the penis also showed experiential differentiation. With sexual experience prior to the penile nerve cuts (PNX), the IL increased five fold over the sham operated control (142,150,198). The males given no prior experience had a substantially larger IL increase (149). No consistent changes over repeated testing were observed in either case. Similarly, the application of an anesthetic to the penis resulted in increased ILs (1,83). Other manipulations, such as severing the fifth nerve, innervating the snout and vibrissae, resulted in an increased IL (14) as well. However, if more than one sense were interrupted (included OBX, blinding, 5th nerve) no sexual behavior occurred (14), making the IL nonexistent or as long as the test period. The only attempt to interfere with hearing was a repeated loud bell, which increased the IL six fold; but too few males were used to demonstrate statistical significance (51). Finally, electrical self- stimulation of the hypothalamic ”pleasure" area to the point of ejacu- lation produced no IL change when tested afterward with a female (4). 163 Hormonal Variables Like the sensory manipulations, hormonal effects produced only increases in the IL compared with normal intact males. The hormone effects were categorized by gonadal hormones, androgens (excluding testosterone), drugs, and a miscellaneous grouping. The initial gonadal hormone treatment was castration. Castration resulted in an exponential rise in the IL up to almost a six fold increase over the intact IL (58,60,198,205). The rise began at approximately one and a half days postcastration. In castrate males, daily injection of testosterone propionate (TP) returned the IL to normal intact duration. Uhder a maintenance regime, 100 ug of TP was sufficient for normal ILs. At lower dosages, the IL seemed to increase linearly with decreasing dosage (28). No significant changes occurred over the days of injection at the higher dosages (198,205). Under a recovery regime, a higher sufficient TP dosage was indicated. Extrapolation of the Sgdersten data (177) indicated a dosage of about 350 ug TP was required to produce a normal IL. Lower doses resulted in commensurately higher ILs. The higher sufficiency level was consistent with other, more limited data (181,144). The effects of estrogen injection were more difficult to interpret. In castrate males, high EB doses (70-150 ug) apparently maintained normal ILs (59,82). Under recovery conditions, the results were equivocal. The castrate males treated with EB had reported E/C ratios of 0.222 to 5.333 (144,164,166,l76,177,181) for dosages of 0.5 to 100 ug. However, a weak trend of increased ILs at 164 the higher EB dosages was observed. In intact males, an increasing dosage of EB resulted in increasing IL values (with a decreasing number of males intromitting in one study)(59). However, no statistically significant change in IL with increasing dosage occurred in another study (176). In both cases, the IL was elevated. Androgens Dihydrotestosterone (DHT) did not return the IL to intact levels. DHT (500-1000 ug) in castrate males resulted in about a two fold IL increase over intact males (l44,l64,177,205) under either a maintenance or recovery regime. No change in the IL level occurred over 14 days of injection (205). When EB (.05-50 ug) was combined with DHT (1 mg), the IL was reported at intact levels (144,198). No obvious change was observed over the EB dose range (144) or over 12 to 40 days of injection (198). If estrone (1-5 ug) was substituted for the same dose of estradiol and combined with DHT (500 ug), the IL was three times longer with the estrone combination (145). Furthermore, the combi- nation of higher doses of DHT (500-1000 ug) with 1 mg T (141) or 200 ug TP (177) kept the IL at normal levels. Androstenediol (AEOL) was just slightly less effective than androstenedione (AEONE) in returning the IL to normal levels. AEONE effected normal ILs with at least 100 ug dosages (46,157,164) under recovery regimes. At the same dosages, AEOL was slightly less effective, as demonstrated by the ratio of AEOL/AEONE I 1.12 (46,157). 165 There was no change from the intact IL under a maintenance regime out to 70 days of injection (205). DHT was less effective than either AEONE or AEOL. Hypophysectomy and Adrenalectomy Hypophysectomy when combined with castration significantly inhibited the castration IL rise for at least three weeks after surgery (165). Adrenalectomy proved ineffective in altering the ILs of either intact (48) or castrate (48) males, or when castrates were given testosterone (48,82) or EB (82). Drug Treatments The nonsteroidal androgen analogue, Fluoxymesterone (FM), did retard the increase in IL following castration or the cessation of TP treatment (198). With FM, a rise in the IL started at approximately 21 days of injection and attained a plateau at a three and on half fold level after 28 days injection. This rise never attained castration IL levels, and the IL rise was maintained well beyond the termination of all behavior following castration. When PNX was com- bined with FM injections, the effect of FM injection was equivalent to that of TP. The PNX took precedence over any effect of PM (198). Anti-androgens did not alter the testosterone maintained IL. Cyproterone acetate (CYA)(10 mg) did not alter the IL of castrates (49) or those given TP (49,204). Similarly, Flutamide (FL)(20-25 mg) 166 injection of intact or TP treated males proved nonsignificant (180). The IL changes due to anti-estrogens were more pronounced, but inconsistent. MER-ZS produced decreasing ILs with increasing MER dosage (2-28 mg) in T injected males, but the decrease was nonsignificant. ICI, however, showed a definite, but nonsignificant, IL increase at the highest dosage (0.1-1.0 mg/kg BW) in T treated males (47). On the other hand, gig-clomiphene (.25-1.0 mg) caused no noticeable change in the IL (47). Overall, a lack of effect of the anti-estrogens must be concluded. The aromatase inhibitors also proved of no use. They did not inhibit the effect of a single injection of TP (6 mg). Both metopirone (10,22 mg) and androstanedione (2.5-5.0 mg) were ineffective (47). Aminoglutethimide (5-15 mg) had no IL data as the males did not intromit (47). Again, none of the drugs interfered with testosterone action. FM proved to act like an intermediate strength androgen. Synopsis When sexual behavior began to degrade, the IL increased, and only decreased in response to non-noxious stimulation. The obvious cases where behavioral degeneration occurred, such as castration or low testosterone dose, resulted in an increased IL. The other androgens and FM demonstrated degrees of IL recovery and maintenance. Estrogen had either no effect on the IL, or insufficient dosages were reported to demonstrate one. The removal of sensory stimulation, i.e., sensory organ removal, 167 was uniformly effective in increasing the IL. This was an expected result, as the loss of a sensory modality would be debilitating to some degree. Decreases in the IL occurred for low levels of shock, an "excitatory" stimulus. However, if the intensity of the shock was increased, it became a noxious stimulus, as demonstrated by the increase in the IL. The same held for an ECS. In addition, the lack of adequate sexual experience, very young or old age, frequent testing, or testing during the rat's light period all proved to increase the IL. The extremes of most common variables also appeared to be debilitating. 6.3 Intromission Frequency The Intromission Frequency (IF) is defined as the number of intromissions occurring during the interval from the first intro- mission to the ejaculation of each ejaculatory series. The IF is subscripted based on the particular ejaculatory series measured. For example, the first IF (IFl) for a group of males is the average number of intromissions occurring prior to the first ejaculation, and the intromissions following the first PEI to the second ejaculation is the second IF (IFZ). The numbering continues to sexual satiety or the test termination. Approximately ten intromissions occurred during the IFI. The IF1 study means indicated differences between strains. The theborg males had the highest IFl of 13.2 :_0.4 (n I 23 studies), and the Sprague-Dawleys had the lowest of 8.6 1:0.4 (n I 9 studies). The remaining strains fell at about 10 intromissions. The range in 168 the IFl reported in individual studies (nI85) was from 6.5 to 20.3. Over five consecutive ejaculatory series, the IFI was the maximum IF. The IF2 was approximately 50% of the first IF. The IF3_5 gradually increased with successive series, at least to the end of the fifth series (30,62,74,102,119,125 - reporting 4 or more consecutive series). The strain differences reversed for IF2_5, with the theborgs having the lowest IFs and the Sprague- Dawleys the highest. During the following discourse, the reader should assume no data were available for IF2_5 if no mention is made of these series. The IF changed due to the male rats' age, with the greatest change occurring during the rats' youth. Proceeding from puberty, the IF fell exponentially to adult levels at 165 days of age for all ejaculatory series (64,119,123,128,132,140). Following a stable adult period, the IF gradually decreased, but nonsignificantly, with older age (>312 days for IF1 & >430 days for IF2_5)(70,119,123,132, 140). The time of testing during the rats' dark hours proved to have no significant effect. However, a nadir for IF1_2 was apparent at TDNI4 hrs.(63). Testing during the light phase showed no consistent differences from dark phase testing for IF1-5 (31,119,123). No effect of the test spacing (TBT) was seen for intervals from 90 minutes (44) to 15 days (30,59,119). The lack of effect was maintained over IF2_5 (119). Similarly, no effect of sexual inexperience was observed in adult males (48,64,70,119,158). Furthermore, the raising conditions of cohabitation (15,70,87,l39, 169 184) and isolation (15,22,71,87,136,206,208) did not differ from segregation for IF1_2. The introduction of a screen between males or between males and females was also ineffective (184). Behavioral and Stimulus Variables The enforcement of an interval between intromissions (EICI) decreased the number of intromissions in an ejaculatory series. With increasing EICI length, the IF decrease was rapid and exponential, and it attained a minimum value by an EICI of 5 minutes. With longer intervals, past 30 minutes in duration, the IF gradually returned to 2§.l$23 values (40,129). The degree of the EICI-IF decrease could be differentiated by strain. theborg males had the greater decrease (652) for both single (119) and multiple (119,129,131) enforced intervals within a series. The Long-Evans (42,43) and Sprague-Dawleys (91,131) produced a decrease of 422. The response pattern was evident for all five series (42,119,128,129,l31). The response to EICIs was influenced by the number of intromissions (I) allowed prior to the enforced interval; the greater the number of prior Is were, the greater the reduction in the IF (42,129). Enforcement of an interval following an ejaculation (EPEI) increased the IF of the following series, and the increase grew with increasing EPEI duration. As with the EICI, the EPEI effects could be differentiated by strain. The theborg IF increase was slightly more rapid and based on a square root function (121,122,125,130), while the rise in other strains (39,67,68) followed an "e" function. 170 In all strains, the IF2_4 rose to approximately twice their normal value with EPEIs of more than 4 hours. Recalling that the IF2-5 was usually one-half of the IFl and the EPEIs when sufficiently long approached intervals between tests, the doubling of the IF2-5 becoming the IF1 of a new behavioral sequence of the next test. No interaction of the EICI and the EPEI was indicated (130) and the multiplication of the model ratios for both EICI and EPEI provided a reasonable IF response. However, the study gave only one manipulation of the EICI variable for a range of EPEI values. The manipulation of both variables in conjunction would be required for a complete test of an interaction. The exchange of a new female for the original female was ineffective on the IF when the exchange occurred at each ejaculation (6,62,67,68,77,101,102,207). However, when the exchange was made only at sexual satiety, a nonsignificant increase (r I 1.20) occurred (56,74,116,207). With a 60 minute EPEI added to the female exchange, the rise in the IF5 was depressed from the height of the EPEI treatment alone (62). IF1-4 were not affected by the application of shock at low _ levels (below the pain threshold)(6,23,50,52,81,171,173). However, at high shock levels, the IF1 was drastically reduced (23). Electra-convulsive shock (ECS) also decreased the IF (26), but to a much lesser extent than the high shock. The use of shock for avoidance conditioning reduced the IF only when the E§.l$23 tests occurred in the same cage used for female avoidance training (24,97,208). The testing of trained males in novel cages reduced the conditioning effect (24,208), somewhat. A 171 one-half reduction in the test arena size decreased both the non-shock and shock groups for IF1-2 (50). Other conditioning paradigms produced increased IFS. When a light (CS) was paired with copulation (UCS), the IF1 was increased, but not IF2-3 (119). Pairing a loud bell (CS) with copulation increased the IF1-4; the greater effect occurred during the IFl (119). Training to bar press or pull for access to the female proved ineffective over IF1_4 (104,119,173). However, when shock during testing was added to prior bar press conditioning (173), the treat- ments were synergistic. Neither treatment produced a significant ef- fect alone, but together they substantially reduced the IFI (r I 0.50). Testing males and females in groups significantly reduced the IF1 in males of all ages (119,120).' The reduction in IF2_5 was far less, but the reduction was greater in the older males (25 mos.)(ll9). The reduction was even less when the three male-female pairs were tested in three adjacent arenas simultaneously (119). Handling the male during testing also reduced the IF, but only in old males and only for the IF1 (68,132). Some stimulus object manipulations reduced the IF. Exposure of males from 37 days of age to a receptive female or another male in a testing arena reduced the IFI as adults compared with males given no early exposure (105). The sexual stimulus of a nonreceptive female, a young male, an immobile estrus female, or a small guinea pig resulted in no display of the intromission pattern by inexperienced male rats (13,14,17). McLean st 31. (156) reported an interaction among female stimulus rats from different strains. The Long-Evans female was the most preferred and the Wistar female was the least 172 preferred by all males. The Long-Evans males were the least discriminating among the females. In general, males preferred females of other strains. However, the data for intromissions was reported as total Is/30 min. test, not as IFs, and the totals were unusually low. Males given 40 minutes with a vaginally closed female prior to sexual testing had significantly reduced the IFI (88). Exposure to a c0pulating pair for the same time had no effect on the IFI (90), and neither did the wearing of a long collar to prevent genital grooming affect the IFI (96). Similarly, electrical brain self- stimulation had no effect (38,55). The IF was not particularly sensitive to the behavioral and stimulus treatments. Shock designed to arouse the male proved inef- fective, as did providing a new stimulus female, except at satiety. The EPEI forced the IF to return to levels approximate to those at the beginning of a new test when the EPEIs were sufficiently long. However, when effects on the IF did occur, they were usually decreases, such as for group testing, access to a VagX female, avoidance conditioning, high shock, EICI, ECS, half sized arena, and sexual stimuli other than the normal receptive female. Sensory Variables The interruption of sensory input to the central nervous system tended to decrease the IF, at least, due to the removal of stimulation from the nose or penis. Blinding was ineffective. Olfactory bulbectomy (OBX) did lead to decreases in the IF for 173 both sexually experienced (14,98,100,l37,l38,196,206) and inexperienced (14,139,168) male rats (r I 0.86). Males made peripherally anosmic, without brain injury, were comparable to the OBX males (138). Several manipulations of sensory input from the penile area were attempted. Anesthesia of the penis either eliminated intromission (53) or interfered (l) with its display. Removal of the penile bone greatly reduced the IF (27). Severing the nerves innervating the penis inconsiStently affected the IF1_3 (142,198) of those experi- enced males that responded; no clear change was evident. The only potential exception was an enhancement of the effect of castration (198). In any case, intromissions did disappear by the third series ,in PNX males castrated and injected with TP or FM (198). Neither blinding (14,89) nor severing the facial nerve (l4) affected the IF. However, if two or more sensory modalities were eliminated, all the males failed to achieve intromission (l4). Hormone Variables Castration caused a decrease in the IF. A decrease to 60% of normal intact levels in IF1_3 (49,58,59,159,l62,l65,l88,l98) was evident by 6 to 7 days postcastration, and was maintained to at least 35 days postcastration. However, no pattern of decrease immediately following castration was provided. Castration was the precondition for almost all the following hormonal treatments. Testosterone treatment effected no consistent changes after seven days with injection under either the recovery (136,165) or maintenance (159,198) regimes using 75 ug (159) or approximately 500 174 ug (136,165,198) T or TP. A dose response became evident only with less than 100 ug or less than 5 mm lengths of T filled, silastic implant. An exponential decrease in the TTP/intact ratio for the IFI was indicated with a 2 mm silastic implant (57) and by 50 ug TP or less (28,177). The exponential coefficients for the two delivery systems gave a relationship of 14.7 ug TP for each millimeter of T implant. A single injection of TA (10 mg) maintained normal IFs for nearly 8 weeks, twice that for TP at the same single dose (33). The IF responses to estradiol (EB) were difficult to interpret. No single study provided a dose response relationship. Sgdersten (176) reported no change from the castrate IF for 5 to 200 ug/kg BW. Simi- larly no consistent change over dosages of 0.5 to 70 ug EB generated from several studies (11,59,144,164,166,176,177,l81,l98) was evident. The variability in the IF ratios (EB/TP r I 0.26 to 2.26) was very high, with a majority of the high ratios at the 5 ug or less dosages. A major problem was the low number of males responding to the EB (the IFs were based only on the responding males). Possibly, when sexual behavior degenerates, the IF increased in some males and decreased in others before intromissions disappeared, thus accounting for the high ratios in some groups and low ratios in others with little regard for dosage. The model assumed an increased IF for the lower EB dosages. The IF tended to decrease over days of treatment (5,59) with high EB doses (70 ug & 100 RU) under maintenance regimes. With a recovery regime, 100 RU of EB increased the IF from castrate values (5). However, all results for EB should be viewed with skepticism due to the inconsistency among studies. The IF was consistent with a normal IF when 1 ug EB was combined with TTP (141,177). 175 Androgen Variables The limited data on dihydrotestosterone (DHT) effects on the IF provided no indication of changes. Under a recovery regime, 200 to 1000 ug of DHT(P) showed no consistent change from normal, intact IFI (12,144,152,l64,177). Maintenance with 150 ug DHTP (159) resulted in a possible IFl decrease. In addition, combinations of 200 ug DHT(P) or more with l to 50 ug of EB (11,144,152,l98) or 200 ug TTP or more (143,177) kept the IFl at normal levels. The effect of androstenediol (AEOL) or androstenedione (AEONE) on the IF1 proved an all or none response. Both no intromission (157) and a normal IF (46,164) for both androgens occurred with a recovery regime. The lack of intromission occurred up to the 1 mg dosage. AEOL tended to be more able to induce intromission than AEONE (157). A l9-Hydroxytestosterone (HTP) injection (150 ug) under maintenance conditions had inconsistent results over the five weeks of injection (159). One experiment showed a nonsignificant increase for IFl over the five weeks. However, a replicate experiment had a significantly reduced IF1 at the first week and no intromission by the third week, which approximated the response of the oil injected castrates. Overall, the studied androgens were not particularly effective in demonstrating significant changes in the IF. Intromissions tended to disappear before any consistent change in the IF occurred. 176 Other Hormone Variables Adrenalectomy did not alter the IF, regardless of whether males were intact, castrated, or given TP (48). The addition of proges- terone to EB (7,166) or TP (166) caused no further changes. Also, LH plus FSH in castrate, hypophysectomized castrate (165), or OBX.males (137) caused no significant changes from the control IF. Drugs The IF resulting from fluoxymesterone (FM) injections deviated from normal levels only when penile nerve cuts (PNX) were combined with the FM (198). No consistent deviation in IF1_3 occurred in sham males given 500 ug FM under a 57 day maintenance regime. The FM-PNX males showed a consistent, increased IFl (r I 1.48), with no pattern of change after 4 days with injection (198). The combination of FM and EB (50 ug) increased the number of intromissions over those for castrate males (103). Anti-androgens had some effect on the IF of intact males and equivocal effects on castrate males. Cyproterone acetate (CYA) produced a nonsignificant increase in castrate males (49,152), but produced no change in TP injected males (49,204). Flutamide (FL) caused nonsignificant decreases in intacts, castrates, and TP injected castrates (180). None of the anti-estrogens studied indicated any change of a TP replacement IF. The drugs included HER-25 (47), CI-628 (202), gig- clomiphene (47), and ICI-46474 (47). Similarly, MER-25 (10 mg) with 177 DHTP did not differ from DHTP alone (12). The aromatase inhibitors, like the anti-estrogens, proved ineffective in influencing the IF in TP treated males. Several milligrams of metopirone, aminoglutethimide, or androstanedione did not alter the IF of responding males (47). However, AGT eliminated intromission at both 5 and 15 mg dosages (47). Overall, neither the anti-androgens, anti-estrogens, nor the aromatase inhibitors significantly altered the IF. However, IF decreases were seen with CYA, FL, Metopirone, and AGT. The reality of these decreases has remained in question, particularly, because some of the drug and concomitant control treatments reduced the number of males attaining intromission. Synopsis The IF remained relatively unperturbed by any experimental treatments. When changes did occur, the IF was depressed in the majority of situations, such as the manipulations of behavior and sensory input. The variables effecting increases included young age, a fresh female at satiety, EPEI, two types of classical conditioning, and response to EB, TA, and a couple of TTP paradigms. On the whole, the IF provided no discrimination among the different variable classes, with the possible exception of a relative lack of response to the drugs. The IF was apparently either a very stable measure or so variable that differences could not be statistically established until the entire pattern of the sexual behavior began to degenerate. When IF changes did begin to appear, there was no consistent means of 178 ascertaining whether the IF change would be positive or negative. 6.4 Ejaculation Latency The ejaculation latency (EL) is defined as the time (in seconds) from the first intromission to the ejaculation of each ejaculatory series. Each successive EL is subscripted according to the particular series. The first EL (ELI) is the longest, followed by the ELZ, which is usually the shortest. Continuing from the ELZ, the ELs increase with each successive series, at least to the fifth EL. In addition, the increase is greater with each successive EL. The ELI differed among the various rat strains. The Goteborg had the shorter ELI at 398 j; 38 sec. (E : SE)(n =- 9 studies). The Long-Evans with an ELI of 480 :_40 sec. (n - 15 studies) fell in approximately the same range as the Wistar males at 466 1:107 sec. (n=8). The higher EL1 durations were from the Sprague-Dawley males at 590 i 57 sec. (n=5) and the mixed grouping at 590 i 59 sec. (n-IO). The EL was affected at both very young and older ages. ELI followed an exponential rise preceding from about 200 days of age toward puberty (119,128,140). This pattern was repeated across all five series (EL1_5). The pattern of change in the older males (>600 days) was more gradual; it appeared linear (119,124,132,l40). The old male pattern also was maintained over consecutive series, with some decrease in the rate of increase with age due to increasing series. The EL was altered during the rats' light cycle. EL1-2 were highest when the dark phase began and decreased exponentially to 179 their shortest duration by the end of the dark period (63). When testing occurred during the light phase, EL1_5 was consistently longer (r I 1.67) than the congruent hour during the dark phase (119,123). Reducing the number of days between consecutive sex tests increased the duration of the E11_3 when the testing intervals were three days or less (30,76,119,121). These males were tested to at least three ejaculations. To some extent, repeated testing, resulting in greater sexual experience, decreased the EL. The increased EL1-5 (r - 1.60) due to sexual naivety was inconsistent. Mbst studies reported increases (48,64,70,127,158,l69), but statistically significant effects were rarely found. Any noticeable difference between the inexperienced and experienced males was gone after three sexual tests. The condition of caging from weaning had little effect. Cohabi- tation produced no effect on the adult EL1_2 (70,87,184). Isolation, especially at Day 2 of life, resulted in some ELI reduction; however, the reduction did not attain statistical significance (87,184). Sepa- rating the experimental males by a screen from a female had no effect, but when males were separated from another male, a decrease in the ELI occurred (184). Behavioral and Stimulus Variables The introduction of an enforced interval during sexual testing usually produced an increase in the EL. Enforcing a one minute interval between intromissions (119,130) tended to increase EL1_4, 180 but no evidence of statistical significance was given. The model assumed an increase (r - 1.37). An enforced PEI substantially increased the EL. EL2_5 increased with increasing EPEI, logarithmically, to durations comparable to a normal ELI and above (39,67,68,121,122,125,l30). Again, the extended EPEIs were consistent with the short intervals between separate tests. In general, E11 values were attained by EPEIs of 30 minutes or more. EL lengths 50% greater than the ELI occurred with EPEIs of 24 hours or more. No interaction of the EPEI with the introduction of a fresh female was reported (67,68). The introduction of a fresh female after each ejaculation (62,77,101) tended to decrease the EL (r - 0.85). However, changing the female after a single ejaculation provided less consistent results (67,68). Furthermore, introducing the new female only at satiety failed to influence the subsequent EL (45,56,74,77). A shock stimulus produced significant decreases in the EL length. The effect was less pronounced after the first EL in sexually experienced males. The ELI ratio (shock/NS) average (r - 0.59) had great consistency across studies (6,52,81,17l,l73). The ratio (r - 0.75) for EL2-3 (6,52,171) was less consistent. When electro- convulsive shock was used, the reduction in the EL was very similar (r - 0.69)(26). The addition of a bar press for access to the female tended to eliminate the effectiveness of the light shock (173). Some evidence was available indicating an effect on the EL due to avoidance conditioning, but no effect was evident for positive re- inforcement paradigms. A loud bell, a negative reinforcer, paired to mounting (119) significantly increased EL1_4. However, presenting 181 a shock as an avoidance stimulus to copulation resulted in a decreased EL (r - 0.83) when testing took place in the conditioning cage without shock. When testing occurred in a novel arena, the effect of prior shock conditioning disappeared (24). The conditioning was situation specific. The loud bell apparently disrupted ongoing sexual behavior to result in a lengthened EL, but the anticipation of shock effectively produced a facilitation, a reduced EL. On the other hand, a bar press for access to a female, positive reinforcement paradigm, produced no change in EL1 (173). Furthermore, the bar press paradigm insulated against the effect of ongoing shock. Testing multiple males and females as a group (3 pairs) substantially reduced EL1-3 of both adult and old males (119). The effect tended to disappear for EL4_5. The same effect occurred, but to a reduced extent, in copulating pairs tested in adjacent arenas (119). The group testing effect was eliminated if testing occurred during the rats' light phase (120). Other manipulative treatments proved ineffective. Electro- ejaculation prior to testing (4), prior electrical brain stimulation (55), and long collars (96), preventing genital grooming, were all ineffective. 0n the other hand, some stimuli did shorten the EL. Handling the male during testing reduced the EL1-3 (132), but the effect was more pronounced and statistically significant for the old males (20-25 mos.). Both exposure to a vaginally closed female (88) and exposure to, but no contact with, a copulating pair (90) for 40 minutes prior to testing significantly reduced the ELI. 182 In general, environmental and sexual stimuli depressed the EL. The change to a new female at each ejaculation, shock during testing or conditioning to a ”shocRing" environment, electroconvulsive shock, group testing, handling, or exposure to incomplete sexual stimuli, all decreased the length of the EL. Only enforced 1013 or PEIs and the conditioning to the negative stimulus of a bell proved to increase the EL. Sensory Variables Unlike the effects of sexual and environmental stimuli, removal of a sensory organ or disruption of sensory input consistently in- creased the EL duration. Olfactory bulbectomy (OBX), blinding, and removal of penile sensation had an inhibitory effect, an increased EL. The elongation of the EL due to OBX was large. The response ratio (OBX/sham r - 3.60) for ELI was definite for experienced males (45,98,100,l37,l38) and indicated for inexperienced males (206). Additionally, a lessening of the OBX effect was indicated over consecutive ejaculatory series (45). Blinding the males increased the EL1_2 (r - 1.86)(89), but not as substantially as OBX. Reduction of penile sensation also elongated the EL. Removal of the glans penis (183) significantly increased the ELI, while penile anesthesia (142) eliminated ejaculation and, therefore, the EL. Severing nerves innervating the penis and genital area (PNX) produced the largest EL increase in sexually experienced males. The 183 ELI rose to three times normal value when the dorsal penile nerves (142,198) or the pudendal nerves (118) were sectioned. A decreasing effectiveness of the PNX.was demonstrated (198) with consecutive ejaculatory series, reaching normal durations by the EL3. However, ejaculation was virtually eliminated by the third series. Hormone Variables Castration produced a gradual and approximately linear increase in the ELI (59,198,205) with increasing days postcastration. Pos- sibly, this effect was present only for the ELI. Some data (198) showed no change from control levels for EL2-3, but very few males attained ejaculation in these latter series. A secondary factor, the age at castration, further increased the ELI, as the age of castration decreased from about 13 days of age (133,135). Testosterone injection (SO-3000 ug) of castrates reportedly induced intact ELs. No data for less than 50 ug were available to establish a dose response for the EL. Recovery was complete with 50 to 1000 ug TP (177) or 300 to 3000 ug T (157). Similarly, dosages of 2 to 60 mm length silastic implants of T (57) maintained the EL at intact levels. No change was seen over 70 days of injection (198,205) under a maintenance regime at higher TP doses (2 500 ug). A single injection of TA (10 mg) maintained normal EL values out to 8 weeks postinjection, but TP (10 mg) maintained EL to only 3 weeks (33). The EL was highly responsive to testosterone, as other behavioral measures showed changes at the same low dosages. Estrogen was less effective than testosterone. The estrogen 184 data were highly inconsistent, and comparisons with castrated male controls were rare (no doubt due to the lack of behavior). No data were available giving a dose response. Different dosages from different studies had no observable pattern. From 1 to 100 ug EB, the EB/TP-intact ratios varied from 0.94 to 2.28 (ll,59,82,l64,176, 177,181). There was some tendency for low doses (1-2 ug) to have higher ratios, and for experienced males to have lower ones. The average ratio (r - 1.52) was assumed for EB injections. Some EL increase over days of injection with EB starting at castration was shown (59), but the most noticeable rise in the EL occurred in intact males injected with EB. The intact EL rose to four times normal with 50 ug EB, and the EL was eliminated with 200 ug (56). Insufficient evidence was available to conclude the injection of high EB doses was analogous to castration in intact males, or that EB injection of castrate males ameliorated the effect of castration. However, the report of a few EL values under a recovery regime with EB (11,164,176,l77) indicated the effect of castration was reduced, because no control males were ejaculating at the later times postcastration. Androgens The androgens studied; DHT, androstenediol, androstenedione, and androstanediol; brought the EL to normal intact levels. DHT(P) at 125 to 1000 ug (12,72,164,l77,205) did not differ from their same dosage TP controls, regardless of the treatment regime. No change 185 over 70 days of injection (205) was indicated. No substantial change occurred with the addition of TP to DHT(P) (12,141,177). The addition of EB to DHT(P) interfered with the DHT(P) sustained ELs. No statistically significant changes were seen with 0.05 to 50 ug EB (11,144), but a pattern of decrease in the EL with increasing EB dosage did appear. The same decrease was seen when free estradiol (1-5 ug) was combined with DHT (145). On the other hand, estrone with DHT (145) produced larger ELs with the same dosage. Both androstenediol (AEOL) (46,157) and androstenedione (AEONE) (46,164,205) maintained the EL at intact or TP control values. The AEOL (2_800 ug) EL was more variable than that of AEONE. The combination of androstanedione (AAONE) with TP (47) did not cause any change from TP alone, but the combination of AAONE (1 mg) and DHTP (200 ug) did significantly increase the EL (12) over the TP control, but not over DHTP alone. Adrenalectomy Adrenalectomy had little effect on the EL, although increases were reported by studies (48,82) of intact and TP castrates. For EB injected castrates, adrenalectomy reportedly (82) increased the EL two fold. Overall, however, due to the limited data, adrenalectomy should be assumed to have no significant effect on the EL. 186 Drugs The androgen analogue, fluoxymesterone (FM), maintained normal EL levels to a degree. When compared with T? controls, the castrate FM males, both PNX and sham, produced a gradually increasing EL, at least to 56 days of injection (198). The increase over time did not match a castration (oil control) increase. Furthermore, the FM extended ejaculation and the EL beyond the point of termination for oil controls. In addition, the EL1_3 FM effect was reduced with increasing series (198). FM stood intermediate between the same dose of TP and castration alone in its effect on the EL. Neither of the anti-androgens affected the EL of castrates or those given TP replacement. Cyproterone acetate (10 mg) (49,204) and Flutamide (25 mg) (180) were both ineffective. Among the anti-estrogens, only MER-25 produced any change in the EL. HER-25 shortened the TP maintained EL significantly (r - 0.58) at the 2 mg dosage (47). However, the EL ratio (T+MER/T) then increased to r - 1.34 with 28 mg. 01-628 (10 mg) (182), Eigfclomi- phene (0.25-1.0 mg)(47), and ICI-46474 (0.1-1.0 mg)(47) produced no substantial EL changes of T replaced males. The aromatase inhibitors were more effective. Both 10 and 22 mg of metopirone reduced the EL, but not to a level of statistical significance (47). AGT reduced the EL to the point of eliminating ejaculation and the EL (47). The effect of a drug on the EL, if any, was always an EL decrease. 187 Synopsis The EL was a relatively consistent measure like the PEI. The extremes of the intrinsic variables and testing parameters increased the EL duration. Increases occurred in such variables as age, sexual experience, test time, and time between tests. Manipulations of behavior and sexual and environmental stimuli; such as EICI, EPEI, shock, group testing, and handling; reduced the EL. Conversely, the sensory organ variables (e.g., OBX and PNX) increased the EL. Castration caused an increasing EL. The addition of TTP and other androgens returned the EL to precastration length. Estrogens gave indications of some retardation of the castration EL. However, estrogen also inhibited the action of androgens, because it effected EL increases in intact males and in combination with DHT. The nonsteroidal androgen, FM, produced an intermediate response, between that of castration and equal TP dosage. Finally, the drugs that were effective; MER-ZS, ACT, and metopirone; decreased the EL supported by testosterone. 6.5 Ejaculation Frequency The ejaculation frequency (EF) is the number of ejaculations achieved during a sexual behavior test. Because the length of the test (TMIN) directly limits the possible number of ejaculations, the length is of paramount importance. The relationship of the EF to the. TMIN (min.) was linear (EF - 0.068°(TMIN)), until satiety was approached (n - 33 studies). Unfortunately, no data were available 188 between the 90 minute tests and tests to sexual satiety. The average EF for satiety tests was 6.8 ejaculations; it served as the upper limit of the EF. No indication of differences due to strain were seen for tests of 90 minutes or less, but strain differences were present with satiety. The Long-Evans (41,56,62,67,74,1l6,207) and theborg (140) males satiety average was EF - 6.80 1:0.16, and the Sprague-Dawley (101) and the mixed group (30,77) averaged at EF - 5.90 i 0.06. The relationship of age to the EF was an inverted "U” shape, a hump, with the highest EF values during the adult ages. At the younger ages (<250 days), an exponential increase in EF occurred with increasing age (119,123,140). The decrease in the EF after 560 days of age was more linear (119,124,132,l40). The old age decrease was apparently due to a decreasing rate of copulation during a set time, because when given unlimited time to attain satiety, adult EF values were attained. Testing variables decreased the EF. When males were tested during the light phase, the EF was depressed (r - 0.70) compared to testing during equivalent times during the dark phase (31,119,123). The EF was also decreased by reducing the interval between repeated tests to less than 7 days. The decrease was directly proportional to the shortness of the test interval (30,44,76,ll9). Prior sexual experience improved performance over that of inex- perienced males. The rate of EF increase due to sexual experience was influenced by the test length (THIN); as the test duration lengthened, the rate of EF improvement decreased (62,70,127,l96). As might be expected, males cohabiting with females prior to testing had a 189 greatly curtailed sex experience effect (70). However, even with males considered sexually experienced, an effect of repeated testing occurred, athough minor (3,45,50,70,76,101,ll9,124,127,188,l92,l98). The increase in the EF disappeared by the third test. When the condition of rearing or caging was considered, no differences among the three conditions were observed. Neither cohabitation (70,87,184) nor isolation (71,87,184) were different from males raised under segregation conditions. Placing separating screens within the cages, similarly, had no effect on the EF (184). Behavioral and Stimulus Manipulations Enforced 1019 resulted in a decreasing EF with increasing EICIs greater than 1.5 minutes (119). The EF decrease followed the same linear pattern, regardless of the number of 1613 experimentally manipulated. Insufficient data (67) were available to establish an EF pattern for EPEIs. Dewsbury and Bolce (67) indicated a decrease due to an EPEI of 60 minutes when males were tested to satiety, but the treatment attained staistical significance in only one of two experiments. When a new female was introduced at satiety, the EF increased (r . 1.14) (34,56,74,ll6). However, if the new female was exchanged for the original female at each ejaculation (76,101) or after 90 minutes of testing (45,67), no change in the EF as evident. Another "excitatory" variable, shock during testing (50,52), elicited an increase in the EF for tests of 60 minutes duration or less (r a 1.35). The rate of shock delivery did not significantly 190 affect the overall shock increase. 0f the conditioning variables, only the conditioned avoidance to a loud bell provided a significant decrease in the EF (119). Neither of the positive conditioning paradigms, copulation paired to a light or a pedal-pull for access to a female, proved effective (119). The BF response to environmental stimuli was inconsistent. Reducing the test area by half decreased the EF (50), except when shock was given in addition, at least, for a 15 minute test. Group testing augmented the EF of one hour tests, significantly in one study (119) for both adult and old males and not significantly in another study (120). Testing male-female pairs in adjacent arenas produced EFs intermediate to group testing and the single pair, isolated arena, control EFs. When males were handled during testing, an interaction was found. A significant increase occurred for the EF of old males (20-25 mos.), but not for those of adult age (5-6 mos.) (132). Sensory Variables The response of the EF to removal or reduction of sensory input was uniform in direction. When effects occurred, the EF was reduced. OBX (l4,45,98,l38) and peripherally induced anosmia (138,196) reduced the EF by almost one-half for test durations of 90 min. or less in experienced males. The lack of sexual experience further reduced the EF (196), as did raising the males in isolation prior to anosmia treatment (196). Blinding, however, did not alter the EF (14,89). Interference with information derived from the penis drastically 191 reduced the EF. Removal of the penile bone (27) eliminated ejacula- tion. Severing the dorsal nerves of the penis greatly reduced (r = 0.18) the EF of experienced males (198), but PNX did not eliminate ejaculation. Without doubt, interference with input from the penis was more devastating to the EF than the removal of smell. Hormonal Variables Castration induced an exponential decrease in the EF. A zero EF value was reached by 36 to 42 days postcastration when tests were 15 (188) or 20 minutes (198) long. When castrate males were injected with 500 ug or more of TP (20,134,188,198), the EF was comparable to an intact male's, regardless of the injection regime. Although no data were available for lower TP dosages, an exponential approach to the castration EF with decreasing TP dosage was expected. EB was unable to return the EF from castrate to intact values (20,103,198). However, an indication that the EF may be held above the castrate falloff under maintenance (103) was noticed; but EB may be ineffective under a recovery regime with long-term castrates (20,198). In either case, the data were very scanty, so any conclusions were speculative. Data for DHT(P) was even more scanty. DHT appeared a poor substitute for testosterone; it did little to return the EF of castrates to normal intact values (198). A noticeable improvement occurred with the addition of EB to DHT (198). Little data were available for the hormone treatments, because most testing was to the end of the first PEI. For a better description 192 of hormonal effects upon ejaculation, look to the ratio of males responding (PEPIPM section). The model assumed a castrate EF for all androgens not provided with data. Drug Variables The only data provided for the EF for any drug variable was for the androgen analogue, fluoxymesterone (FM). Under a maintenance regime, FM prolonged the EF compared with castrates, but FM was not able to maintain the EF at intact (or TP) levels for very long periods. Where castrate males fell to a zero EF by 42 days post- castration, the FM castrates had an extrapolated zero EF by 86 days of injection (198). The FM essentially doubled the duration of the castrate EF response. When PNX.was combined with FM, the drop in the EF was more rapid than castrate controls, but slightly higher than the fall due to PNX castrates (198). However, if at least 50 ug of EB was combined with the FM, the EF stayed approximately at intact levels (103). Synopsis The BF was most prone to decreases in response to experimental treatments. When effects did occur; FM, the hormone variables, sensory variables, and the intrinsic variables (age, test time, TBT, and sexual experience) all provided decreases. As a group, the environmental and behavioral stimuli did not produce effects in the same direction. Variables that may be considered "excitatory", such 193 as a new female at satiety, shock, group testing, or handling of old males, increased the EF over control levels. Only EICIs, negative reinforcement, and reduction of the arena size elicited a decreased EF. 6.6 Mount, Intromission, and Ejaculation Response Ratios (PEPIPM) The measures utilized most frequently in the study of the sexual behavior of the male rat were measures of the relative numbers of males reaponding with ejaculation(s), intromission(s), or mount(s) to any given treatment. The most common representation was the percentage of the total number of experimental males exhibiting ejaculation (PE), intromission (P1), or mounts (PM). Otherwise, the number of responding males in one or more of the three sexual events was reported. The ejaculation measure was the most labile of the three, followed by the more stable intromission measure and the most constant, mount measure. For the purposes of the model and the following discussion, these measures were represented only by their Experimental/Control group ratios derived from the percentage or number of responding males in each of the two groups. For example, if 6 out of a total of 10 castrate males experimentally injected with a low dosage of TP responded with ejaculation and 7 out of the 8 control, intact males responded, the experimental ratio would have been 6/10 - 0.60 and the control ratio would have been 7/8 - 0.875. the model ratio would, therefore, have been E/C - 0.60/0.875 - 0.686. The model assumed the highest ratio of 1.0 as the baseline for 194 each of the E, I, and M ratios. The normal male was generally selected for the ability to copulate, i.e., to attain ejaculation, prior to the experimental testing. Therefore, the "normal“ male was sexually experienced, intact, of adult age, and rested from prior sexual endeavors.- under these requirements, 100% of the males usually responded, so many studies did not report control values for the response measures; that all respond was frequently assumed. Only when the control male treatments deviated from the above was the reporting of both required, and the E/C ratio became necessary. Intrinsic and Test Variables For the most part, variations from the "normal" condition resulted in decreasing E, I, and M ratios (referred henceforth as PE, PI, and PM, respectively). A consistent relationship among the PE, PI, and PM for all variables was always present. The PM was the higher ratio value, closely folowed by or equivalent to the PI, and the lowest ratio was always the PE, simply because mounts were required for intromission and intromissions were required for ejaculation. The PE was, therefore, the most subject to change, making it the most discriminative of the three. Because the PE was the most responsive measure, it will be the most discussed, but the responses of the PI and PM can always be assumed to follow the same patterns of change as the PE but at higher levels. To establish the relationship of the PE, PI, and PM ratios, studies reporting (179,181) at least two of the ratios for normal males over a number of repeated tests were averaged. Over 5 to 10 195 repeated tests, the average PI/PE was 1.07, and the average PM/PI was 1.06. These relative factors were used if no other treatment provided differences between the PE, PI and PM. An altering response to variations in age was noticeable in both young and old males. However, some changes were seen in the adult age group (170-600 days) over the course of a test. As stated before, the experienced adult began at the maximum PE - 1.0 at the first ejaculatory series. With increasing consecutive series, the PE dropped in a sigmoid fashion to approximately PE - 0.52 by the fifth series, the terminus of the model (119,123,127,131,l40). The PE closely approached zero by the eighth series. The PI and the PM after the last ejaculation was about 0.55 (140). A decreasing PE with decreases in the males' age, as puberty was approached, was apparent over all series. The age decreases for each consecutive series were parallel, but at lowering PEs (119,140). A very similar parallel decrease was observed with increasing age (over 600 days). The cessation of ejaculation occurred after fewer and fewer consecutive series with increasing old age (119,123,140). Testing males during the light phase did not significantly re- duce the PE for series one (PE1)(31,119,123). The Light/Dark ratio for the PI was approximately the same (PI/PE - l.018)(3l). Over the following series, the PE - L/D ratio decreased with increasing series number, and the PE approximated zero by the sixth series (PE6) (119). When the time between tests (TBT) was reduced, a reduction of the PEI occurred, but only for tests with fixed time intervals and for TBTs of 2 days or less (119). Testing males to sexual satiety 196 produced no change in PE1-5, but when a 60 minute time limit was imposed, not only decreases with reduced TBTs occurred, but also decreases with increasing series was evident (119). Bermant st 21. (44) demonstrated no effect of low TBT (1.5 - 24 hours) after a 90 minute test. No like data for PI or PM were available. The effects of sexual experience interacted with age, which was not always controlled for. No substantive changes in the PE occurred for males less than 260 days of age (119,127) that could not be accounted for by age effects. Drori and Folman (70) reported substan- tially lower PEs in inexperienced males over 470 days old, but they tested for a little over 15 minutes. Because the Drori and Folman data did not agree with the others, the effects in the model were limited to older males receiving shorter tests (TMIN 3.20 min.). This study (70) did provide relative information on the PI. The PI ratios (Inexp/Exp) started higher at the first test and rose faster than the PE (on the average, PI - PE + 0.40). The caging condition resulted in a divergence in response among the strains. When the isolate condition was compared with the segregate, a gradual increase in the PE occurred over repeated tests. However, the Sprague-Dawleys (80,105)(PEm1n - 0.011) began at a lower PE than the other strains (22,87,206)(PEm1n - 0.026). Under the cohabitation condition, the same strain split was evident. No difference was seen between the cohabitant and the segregate Sprague- Dawley males (80), but a decrease in the PE from a ratio of 1.58 occurred for the remaining strains (70,87). When a screen was placed between two males or a male and female, the PE was equivalent to males raised in isolation (80). 197 The PI of the isolation condition was either equivalent to (87,206) or greater than (86,105) the PE ratio (PI/PE - 1.30). For the cohabitation condition, no change occurred between the PI and the PE (70,87,105,206). The change from PI to PM was slight for the isolation condition (86,87,105,206), producing an average PM/PI of 1.09. Again, no PM-PI change occurred for the cohabitation condition (87,206). Manipulations of Behavior and Stimuli The enforcement of 1013 produced decreases in the PE for one EICI in an ejaculatory series (119). The E/C PE ratio decreased with intervals greater than 3 minutes, and the PE ratio decreases were augmented by increasing series. For example, a 7 minute EICI resulted in a PEI - 0.72, but fell to zero by PE4 (119). No data were available for EPEIs. When a new female was substituted for the original test female at satiety, a small but consistent increase in the PE (r - 1.30) (56,101,207) occurred. With a fresh female at satiety and at each ejaculation the PE increase was larger (r - 2.25)(101). The PI (101,207) and the PM (101) effects were larger than for the PE. Bermant £5.21, (44) provided data demonstrating no TBT effects after the introduction of a fresh female following a 90 minute test; a potential PE drOp occurred only on the third series of the following test for TBTs of 3 to 18 hours. The stimulation of shocks during testing did not affect the PE of sexually experienced males (23,81,174), but the PE of inexperienced 198 males (50,81) was improved. Shock given to castrate males inhibited the falloff in PE postcastration (9). In addition, shock given to very young males (2 45 days) caused males to respond at a younger age with ejaculation (81). Shocks during testing for the PI and PM were affected approximately the same as the PE for experienced and inexperienced males (9,23,50,51,174). The relative increase in PI for castrated males was comparable to that for the PE, but the PM demonstrated a greater increase. Shock maintained a nonzero PM beyond that for the non-shock controls over the days postcastration (9). When shock was given at higher levels, more painful levels, males stopped ejaculating (23). With high shock, the PI fell over a few repeated tests to a zero level, but the PM decrease was more gradual. The PM ratio was initially at a complete response level (PM 3' 1.0). Electroconvulsive shock induced an increase in the PE, approximately double the non-shock control level (23,26). The rise held over several tests. No significant increase due to ECS occurred in the P1 or the PM (26). Shock was also used as a conditioning stimulus. Starting at 38 days of age, males were shocked for approaching a female and tested as adults for sexual behavior, either in the shock apparatus or in a novel arena (208). The shock training produced a statistically nonsignificant decrease in the PE and PI when tested in the shock apparatus. In the novel arena, those decreases were eliminated. Iowever, males conditioned to pull a pedal for access to a female demonstrated no change in PE1-5 (119) over the untreated controls. 199 An alternate change of the test environment was the reduction of the test cage by one-half. The half cage produced a large decrease in the PE (r - 0.21), but the overall decrease was small when shock during testing was added (r a O.765)(50). 'No effect occurred with the P1 or PM. Males tested in groups of males and females showed a PE improvement (119). Adult males had a gradual increase in the PE ratio with increasing series number, and the rise in PE for old males (25 mos.) was greater with later series, when compared to a single pair tested alone. Male-female pairs tested in adjacent arenas had PE increases less than the group males, but slightly better than those tested alone. A similar intermediate response level existed for the old males in adjacent arenas (119). A variety of sexual stimuli produced decreases in the PE, PI and PM. Early exposure (Day 37 on) to receptive female or male stimulus objects produced a decrease in the PE of later tests, but no substan- tial change in the PI or PM occurred (105). When males were actually treated to stimulus objects other than a receptive female as adults, all responses were greatly reduced. A nonreceptive or immobile receptive female, a male, or a guinea pig, sexual stimulus resulted in zero PBS and PIs for inexperienced, isolate males (13,14,17). Regarding the PM, the nonreceptive female was the more effective stimulus (r a 0.575) with the immobile female, male, and guinea pig a weak second (r - 0.20), compared with a receptive female stimulus. When these males received high doses of TP, their PI and PM ratios improved (14,17). Similarly, when a vaginally closed female was the sexual stimulus (200), the PE was zero, but no effective changes were 200 reported for the P1 or PM. The PE, PI, or PM measures did respond to most of the manipula- tions of behavior, testing environment, and sexual stimuli. The manipulations considered "excitatory" increased at least the PE. These manipulations included: a new female at satiety, shock, ECS, and group testing. The treatments of EICIs, high, painful shock levels, avoidance conditioning and alternate sexual stimulus objects appeared to either interfere with ongoing behavior, or provided insufficient stimulation. Sensory Variables The sensory variables uniformly reduced the PE, and often the PI and PM as well. OBX, blinding, facial (5th) nerve cuts, and reduc- tion of penile innervation were effective manipulations. Olfactory bulbectomy (OBX) produced a minor PE decrease (r = 0.80), regardless of the sexual experience in all but one strain (14, 45,98,100,168). The PE of OBX Wistar males was far lower (r - 0.28) (l37,l38,139,206). All Wistar experiments took place in Larsson's laboratory, so the differences may be due to strain. The OBX PI ratio averaged up to double that of the PE ratio, but the PI responses were highly variable (l4,4S,98,l37,l38,l39,168,206) with no strain differences. The PM was only slightly higher than the OBX PI (l4,45,l37,138,l39,206). Peripherally induced anosmia did not differ from the OBX treatment (138). Males raised in isolation had OBX/sham PE ratios further reduced from the "normal" males raised as segregates (139,206). However, 201 those males raised in cohabitation had higher OBX PE ratios (139,206) by a factor of three. The P1 was higher than the PE in OBX, isolate and sham males, but the cohabitants demonstrated little change from PI to PE (139,206). The change in PM due to OBX was not different among the raising conditions. The interactions of raising condition with OBX were based solely on Wistar data. . No significant differences were reported for OBX males given 250 ug TP or 10 IU FSH + 3 IU LH/kg BW (137). Neither hormone treatment compensated noticeably for the effects of OBX. Blinding produced a wide range of results. The PM effects ranged from no change from sham males (185) to an intermediate PM de- crease (84,85) to low levels of response (13). The average PM E/C ra- tio was r - 0.62. The data for the PI and PE response to blinding was scant (13). The P1 was equivalent to the PM, with the PE 20% lower. All penile treatments produced a decrement in the PE and the PI. The reported treatments included removal of the glans penis or the penile bone, anesthesia of the penis, and severing the Pudendal or Dorsal Penile nerves. Removal of the penile bone prevented ejaculation, resulting in a zero PE, and the P1 was severely reduced (27). The PM was unaffected. On the other hand, no change was indicated with the removal of the glans (183). Penile anesthesia, produced with topically applied Lidocain, did reduce the PEI by one-half (1,142), and further reduced the PEZ (1). A limited effect was produced on the P11, and a large decrease occur- red in the P12 (1). The PM was unaffected. Sectioning any of the nerves innervating the penile area 202 depressed the PE by almost two~thirds in experienced males (118,150, 198), and the PE decreased further with increasing series (198). The PNX P1 was approximately 2.5 times greater than the PE (118,198). The PNX PM was not different from controls (118,149,198). The PNX responses of males raised in isolation or given no prior copulatory experience were even further reduced. Isolation (118) reduced the PNX PE almost to zero. The PI reduction was about one-third, but the PM reduction was negligible. The only comparative data on sexual experience and PNX was for the PM (149). The PM was reduced by almost one-third if no sexual experience was given prior to PNX. Males given experience just after PNX did not differ from males given no experience. When PNX males were castrated and injected with DHT(P), the PEs were further reduced, but the P13 were reduced only with extended treatment (198). Beyond the first series, the PI and PM were also reduced. The addition of EB eliminated the interactive reductions (198). Other treatments affected the males' response. Sectioning the facial nerves (13) eliminated the PE and reduced the PI and PM by half. Bursts of loud sound doubled the PI (51), no doubt having some "arousal" effect like shock; unfortunately, this was the closest approach to the sense of hearing. Furthermore, when more than one of the senses were removed, all three measures dropped to zero (13); the males did not respond. 203 Hormone Variables Castration resulted in an exponential decrease in all three measures of responding males. All measures approached zero by 70 to 80 days postcastration. No difference in the dropoff in the PE postcastration was found among the Long-Evans (48,49,58,148), Sprague-Dawley (103,160,205), Wistar (28,160,163,18l), theborg (134) or mixed (32) strains. The dropoff was somewhat more rapid in the PE than the PI (28,103,134,181,186,l98,205), and the PI than the PM (103,134,181,198,205). The postcastration decreases were further augmented with increasing series (58). Testosterone The PE, PI, and PM data for testosterone treatment in castrate males were the best available for any behavioral measure. Sufficient data were provided to separate the data into recovery or maintenance regime categories. The regime data were subdivided into free T or TP studies and sexually experienced versus inexperienced male groupings. The first category was inexperienced males given free T under recovery conditions. The PE, PI, and PM were affected by both dosage and days of treatment. Under recovery, male responses started at zero and followed an exponential increase to approximately 1.0 with extended days of injection of 300 to 1000 ug T (46,47,14l,151,157,l64). The rate of increase over days of daily injection was dependent on the dose. The return of the PM to intact levels began with fewer days of injection than the PI; the PE return began even later. 204 The same pattern of response return occurred with the inexperi- enced males given 45 to 1000 ug of TP (47,133,l35,136,l44,145,l77). As with T, the rate of increase was dependent on the dosage, but the rate was slightly greater with TP. The responses were initiated in the same PM, PI, PE recovery order, but in all cases, the TP injected males began responding earlier than the T males, on the average. When recovery males were sexually experienced, the response to TP was substantially enhanced over the inexperienced males. From 100 to 500 ug TP (12,27,49,72,82,l76,180,181), the rates of increase were larger and the initiation of response was earlier. In most cases, the males were responding with ejaculation after the first day of injection. The age of castration influenced the later adult response to TP. When males were castrated before 13 days of age, the recovery of the PE (133,135) was retarded. The PE retardation increased with earlier ages of castration. With castration at the age of 3 days, ejaculation did not appear (135), and the PI and PM were severely depressed. Under a maintenance regime - using sexually experienced males in all reported cases - low doses of TP held the PE, PI, and PM at normal intact levels. A falloff in the PE occurred only with less than 25 ug TP (32,49). The falloff was more rapid with lowering dosage, until the castration falloff was approximated. Doses of 25 ug to 800 ug (28,32,159,l60,l98,205) showed no consistent change in the PE over 70 days of injection. The same lack of change occurred with 25 ug or more for the PI (28,198,205) and PM (82,198,205), but no data were available for the P1 or PM at lower dosages. Testosterone was delivered in a more continuous manner than daily injections through the implantation of silastic tubing 205 containing crystalline or concentrated T solution. A 5 or 15 mm long T implant maintained the PE, PI, and the PM at intact levels when the implant was inserted at castration (178). The 15 mm implant restored intact levels in males castrated 40 days prior, but no comparative data for shorter implant lengths or TTP injections were available (205). Damassa St El. (57) provided an indication of a dose response in T implanted males on a long-term maintenance regime for the PE. A slight decrease was seen with a 5 mm T implant (r = 0.85) and a greater decrease at the 2 mm size (r a 0.74). Implants of T were also capable of reducing the age for the onset of response (205). Intact males implanted at 14 Days of age displayed ejaculation 12 days earlier (at 31 Days old) than oil implant controls. Similar early responding occurred for the PI and PM, occurring earlier and with higher levels than the PE. The rate of change after onset was approximately the same in the implanted and control males. Testosterone was bonded to different chemical additive that altered the time the testosterone remained in the rat's body. To test their longevity, the testosterone forms were injected in a single, large dosage (10 mg). Under maintenance conditions, testosterone phenylacetate (TA) had comparable PBS to TP, but the P1 was prolonged almost twice the time for TP (33). With a recovery regime, the TA males responded with ejaculation twice as long as with TP (35). Both testosterone cypionate (TC) and testosterone enanthate (TE) lasted three times as long as TP (35). Demonstrable effects were seen with testosterone on the PE, PI, 206 and PM. The PE was the more labile, decreasing earlier with low TTP doses and reaching a zero response before the PI. Similarly, under recovery, the PE was the last to appear and the last to attain intact response levels. In the same way, the PI as more subject to change than the PM. These patterns held regardless of the reductions due to the lack of sexual experience, the age of treatment initiation, the method of testosterone delivery, or the chemical form of the testosterone. Estrogens The categories followed for testosterone were followed for the estrogens, principally estradiol (E2 or EB forms). The responses to estrogen were compared with intact males or TTP (100 ug or more) treated castrate controls. Data were available for recovery and maintenance regimes, experienced and inexperienced males, injection and implant delivery, and combinations of EB with testosterone. The recovery treatments with EB injection produced little (60,143,164,l76,l77,198) or no increase (141,144,152,177) above a zero PE. Zero PEs occurred with 5 ug or less and the small increases occurred with 1 to 200 ug EB with no reliable dose response. The PI from the same studies (60,l4l,l44,152,l64,l77,198) started to increase above zero earlier than occurred for the PE, and attained response levels twice those of the PE. The PM (144,152,164,l76, 177,198) was only slightly more affected than the PI. Experienced males proved substantially more responsive to EB than inexperienced males, at least, at high EB (100 ug) dosages 207 (176). The majority of experienced males responded with ejacula- tion by 16 days of injection, by 8 days for PI, and by 2 days for PM. The recovery increase was less than for the same dosage of TP (176). No comparative data were available contrasting the two estrogen forms, free and benzoate, but some information (145) was available comparing the different estrogens: E1, E2, and E3. The PE and PI did not rise above zero under recovery in inexperienced males with the three estrogens (l 8 5 ug). Estradiol (E2) was two to three times more effective in increasing the PM as either estrone (E1) or estriol (E3). Injection of EB at castration into experienced males (59,82,103) was incapable of maintaining the PE at intact levels with dosages of 50 to 100 ug EB. On the other hand, the PEs were greater than for ,the castrate controls. The PI had some decrease from intact values, but the PM remained at the intact level (82,103). Furthermore, the delivery of estradiol by silastic implant to young intact males (14 days of age) did not significantly alter the development of the early PE and Pl (178). The effect on the PM was comparable to T implants. The combination of EB (1 ug) with TP (200 ug) produced a greater PE, PI, and PM than TP alone under recovery conditions (177). There- fore, EB augmented TP rather than interfered with response to TP. Overall, estradiol, particularly the EB form, produced greater improvement in the number of males responding when they were experienced. The response did not approach that for TTP, however. In many studies of inexperienced males, the PE did not rise above 208 zero. The responses did increase over time under recovery regimes, but the variability among studies made a definite dose response curve difficult to establish. Under maintenance conditions, EB was not capable of maintaining intact levels, but the response levels did not fall to castration values. Although free estradiol and its EB form were not compared, some evidence was provided showing E2 more effective than E1 or E3. Furthermore, EB augmented the effects of TP. The responses to estradiol may best be characterized as intermediate to intact or TP and the untreated castrate condition. Dihydrotestosterone Dihydrotestosterone (DHT) was utilized in both its free and propionate forms. Sufficient data were available to segregate recovery and maintenance regimes, but they were insufficient to separate effects due to sexual experience. DHT(P) was frequently combined with estrogen (usually EB), and sometimes with testosterone. No consistent differences among the reported dosages of 125 to 1000 ug of DHT(P) under recovery conditions were observed. Furthermore, no differences could be established between sexually inexperienced (12,143,144,l45,152,l64,177) and experienced (72,198) males. The PE rose gradually, in most cases, to an average PE of 0.20 after 24 to 60 days of daily injection. The P1 was only slightly higher, and the PM a touch above the PI. Dosages of 150 to 1000 ug of DHT(P) did not maintain the PE at intact levels immediately following castration in sexually experienced 209 males (159,160,163,l98,204). The PE dropped to the r = 0.20 level by 42 days of injection. The PI did not start to drop until two weeks following the PE falloff, but the rate of descent was the same (198,204). The PM started to decrease at the same time as the PI, but the rate of decrease was half that of the PI (198,204). The combination of DHT (500 & 1000 ug) with TP (200 & 1000 ug) increased the PE, PI, and PM over the values for TP or DHT alone (141,145,177). Under a recovery regime, the DHT + TP increases began earlier than those of TP, and the rate of increase was doubled. The combination of EB (.05-50 ug) with DHT (1000 ug) was also a very effective treatment. The increase in the PE for inexperienced males under recovery conditions was far greater for EB + DHT than for DHT alone (143,144,152,l98) and equal to and sometimes greater than a 1 mg TP control (127). The same relationships held with the PI and PM (143,144,152,l98). When E2 (1 & 5 ug), E1 (1 & 5 ug), or E3 (1, 5, & 25 ug) were used in place of EB in combination with DHT (500 ug), the responses were similar to the EB combination with some variation. The recovery PE with E2 + DHT was greater than DHT alone, and showed a greater increase than even the TP (200 ug) control (145). At the same dosages, the E1 proved less effective in inducing total recovery than E2, and E3 was less effective than E1 (145). No statistical comparisons were made between the three estrogens. The TP control PE was closest to that for E3 + DHT. Again, the PI and the PM followed the same relative relationships (145). In general, DHT injections had relatively weak effects on the ratio of males responding with E, I, or M. The recovery with DHT was 210 slow and never attained intact levels, and the DHT was not able to maintain maximal responding over extended treatment. However, synergism occured when DHT was combined with estrogen. The relative effectiveness of the different estrogens followed the decreasing order: estradiol, estrone, and estriol. The combination of DHT with TP produced responses greater than TP alone, but not significantly. Other Androgens Data were available for most of the minor androgens under both the recovery (inexperienced males) and maintenance (experienced males) regimes. The relative effectiveness of these androgens was assessed by comparison with the same dosage of T or castrate controls. For the recovery treatments, the PM was the best comparator among the androgens. The PM for both androstenediol (AEOL)(46,157) and androstenedione (AEONE)(46,157,164) approached that of T, with large variation among the studies. In one case (46), AEONE was equivalent to T and greater than AEOL (1 mg); in another, AEOL was equivalent to T and greater than AEONE (l & 3 mg)(157). The PI and PE were similar between AEONE and AEOL, and these were somewhat less than the T control. The remaining androgens produced very little increase above castrate levels at a 1 mg dose (46). llfirhydroxy-androstenedione and dehepi-androsterone were somewhat more effective than 3a- and 3p- androstanediol, androstanedione, and androsterone. The latter group produced a zero PI, and all the above had a zero PE. Maintenance treatments had a similar relative effectiveness.- 211 AEONE proved effective in maintaining responses at T control levels over 70 days of injection at a 800 ug dose (205). However, at 150 ug, AEONE was only slightly better than the oil castrate (160). l9-Hydroxytestosterone (HTP)(159) and androstanedione (160) demon- strated some ability to retard the postcastration falloff of the PE. However, androsterone, both isomers of androstanediol, and hydroxy- androstenedione approximated castrate PEs (160). A few cases of a combination of androgens were found. When 1 mg of 3fl-androstanediol was combined with 200 ug DHTP, the combination was significantly more effective than DHTP alone in inducing PE recovery (12), but not as effective as 200 ug of TP. The combinations of HTP (100 ug) with DHTP (100 ug) and estradiol diprOpionate (100 ug) with DHTP were both capable of maintaining the PE near intact levels, but were not significantly greater than a 200 ug dose of DHTP (163). The relative effectiveness of the androgens compared with testosterone followed a similar order under both treatment regimes. The PE was the primary response measure. Testosterone was the most effective, closely followed by AEOL and AEONE. The second grouping, showing a lesser effect, included HTP and dehepiandrosterone. An intermediate group included: androstanedione, hydroxyandrostenedione, and DHT. The last and most ineffective group was composed of the two isomers of androstanediol and androsterone. This ordering was far from conclusive as only one or two studies provided the relative responses. The data on AEOL and AEONE demonstrated the variability in relative positioning. 212 Adrenalectomy Adrenalectomy did not alter any of the responses to testosterone injection of castrate males. Neither recovery (48) nor maintenance (48,82) schedules provided any significant changes in the PE. However, adrenalectomy did substantially reduce the maintenance effect of EB (100-150 ug) for the PE, rapidly pushing the PE to almost zero. The EB control responded at near normal levels. No significant effects occurred for the P1 or PM (82). Furthermore, no changes in intact or castrate males (48) were observed due to adrenalectomy. Drug Variables All the drug treatments contained within the model were represented by PE, PI, and PM data. The nonsteroidal androgen, FM, the anti-androgens, anti-estrogens, and aromatase inhibitor groups were all represented. The effectiveness of the drugs was assessed by comparison with the nondrug controls, that were usually TTP injected castrates. Most drugs were expected to decrease the effect of the TTP treatment. The FM data was reported for a maintenance regime only. The FM PE over 56 days of injection was very similar to the same dose of TP (500 ug); only a very small PE decrease occurred toward the end of treatment with FM (198). The minor difference was even less pronounced for the PI and PM. The drOp in effectiveness of the FM compared with TP became more pronounced in series 2 and 3 (198). 213 Furthermore, FM (400 ug) significantly affected the injection of EB (50 ug). The FM when combined with EB maintained the intact PE. The differences between the FM + EB and EB alone were less pronounced for the PI, and both groups performed at normal PM levels (103). The first anti-androgen under consideration, cyproterone acetate (CYA), had recovery and maintenance data. CYA (10 mg) had no effect on castrate males or on DHT treatment under a recovery regime. How- ever, CYA did improve the effect of EB (1 ug) for the PI and PM, and CYA interfered with the recovery rise due to the EB + DHT for the PI and PM (152). The PE did not rise above zero for any recovery treat- ment (152). On the other hand, CYA did not interfere with the PE recovery rise due to TP (100 ug)(49). Furthermore, CYA was capable of maintaining PEs longer than the non-CYA castrates, and the androgen effects of CYA alone were similar to those produced by 8 ug TP (49). The anti-androgen, Flutamide (FL)(25 mg), substantially inhibited the TP (100 ug) PE recovery rise. The inhibition of the P1 was less noticeable, and the effect was not apparent with the PM (180). No androgen effects of FL were indicated when FL was given to castrates or intact males (180). The anti-androgen, SH-7l4 (3 mg), produced a decrease in the PE of intact males (209). The first anti-estrogen under consideration, MER-25, produced ambiguous results. The recovery with TP (800-1000 ug) was not altered by MER (20 mg) for the PE, PI or PM (47,151). However, MER (10 mg) did increase the recovery rise due to DHTP (200 ug)(12). MER had no effect on castrate males (151). The anti-estrogen, CI-628, did significantly reduce the PE re- covery with 800 ug T (151). The CI injections (2.5-4.0 mg) depressed 214 the rate or recovery increase by approximately half for the PE, PI, and PM. When given alone to castrates, it did not induce any recovery. Another anti-estrogen, gigfclomiphene (CLOM)(0.25 & 1.0 mg), did not significantly alter the recovery PE, P1 or PM with 1 mg T (47). On the other hand, high dosages of ICI-46474 did reduce the recovery to the 1 mg T (47). The PE was not significantly depressed for the 40 and 130 ug ICI doses, but statistical significance was seen for the 400 ug dose. The same depression pattern existed for the PI and PM. In fact, the PE was kept at the zero level over 20 days of treatment. The degree of success in depressing recovery with TP by the aromatase inhibitors was similar to that for the anti-androgens and anti-estrogens (47). However, the TP treatment for these drugs was an uncommon one; TP was given in a single injection of 6 mg. Neither Metopirone (20-45 mg) nor androstanedione (5-10 mg) were effective. Aminoglutethimide (AGT) was extremely effective at 10 and 30 mg doses. AGT prevented any rise in the PE and PI, and except for one male, the PM. However, the manner of TP delivery as a single injection raised some doubt as to whether as large an effect would have been produced with repeated TTP injection of lower dosage, as utilized by the other drug studies. The inhibiting effects of the drugs interfering with testosterone or estrogen action were not strictly confined to any particular category of drug. Two-thirds of the anti-androgens, FL and SH; one-half of the anti-estrogens, CI and ICI; and one-third of the aromatase inhibitors, AGT, effectively reduced the recovery increases due to testosterone injection. The AGT appeared the most 215 effective. The synthetic androgen, PM, did maintain responses to a large degree, but not to the full extent of the same dosage of TP. Synopsis The PE proved the most responsive to all experimental treatments. It was potentially the best indicator of changes over time, particu- larly for the hormonal treatments, when sufficient numbers of males were involved. For the purposes of effective modelling, males from two or more studies were necessary, amounting to 15 to 20 males. For the establishment of clear patterns, at least three studies were considered best. The PE, and usually the PI and PM, was affected by intrinsic, behavioral, stimulus, sensory, hormonal, and drug variables. The effects of the sensory variables - OBX, blinding, or PNX - were the the most consistent of all variable classes; they produced only decreases. Age extremes, day testing, short TBTs, and isolation produced decreases. Those variables considered "arousal" or ”excitatory" stimuli produced increases in response; these variables included: a fresh female at satiety, shock, ECS, and group testing. Treatments such as the EICI, high shock, avoidance conditioning, halfcages, and sexual stimulus objects that were not receptive females all produced decreases. The hormone variables demonstrated varying degrees of response. Testosterone injections effected normal intact levels of response at dosages greater than 25 ug. Similar effects occurred with T im- plants. Estradiol induced some improvement over control castrate 216 levels, but not near those of TTP. E1 and E3 were less effective than E2 or EB. DHT(P) proved to be a relatively weak androgen with these measures, producing only small recovery increases and not maintaining responses over extended periods. Androstenediol and androstenedione were the most effective minor androgens, and hydroxytestosterone and dehepiandrosterone were more effective than DHT(P). The deficits with DHT(P) were eliminated when EB was added to the picture. At least some of the anti-androgens, anti-estrogens, and aromatase inhibitors were effective in inhibiting the recovery rise of TTP castrates. The nonsteroidal androgen, FM, was partially effective. Adrenalectomy provoked changes only when combined with EB. Overall, the number of males responding, particularly with the PE, served as a highly effective measure, showing the decay of behavior in a gradual manner, easily observed, rather than the very terminal changes in the other sexual behavior measures such as the IF and PEI. 6.7 Penile Papillae and Weights The penile measures are primarily indicators of the androgenic potency of a variety of hormones on peripheral structures. The model provides information on the condition of the penis because the condition of the penis and the resultant sensory input to the CNS is important to the intromission and consequent ejaculation. The number of cornified penile papillae are counted on a cross-section of the glans penis. The papillae appear as convolutions of the surface of the penis, and they increase the penile sensitivity to stimulation. 217 The penis weight refers to the wet weight of the whole penis, although the glans and the shaft are sometimes weighted separately. The diameter and length of the penis are other reported measures, but they had insufficient data support for comparison. The papillae measure was the most sensitive to changes in the adult rat, as it varied from zero to a maximum; the penis weight had a substantial inherent mass and structure prior to any androgenic increments or decrements. The papillae and weight measures were combined in this summary, because they responded similarly. The average number of penile papillae (PP) or spines in normal control males - i.e., intact, naive males - was 65.5 1:3.3 (i t SE, n = 12 studies) for all strains but the Long-Evans. The Long-Evans average was 87.3 i 13.3 (n I 5 studies). The range in PP number was 47 to 83, with the Long-Evans extending the range out to 109. The penis weights (PW) ranged from 66 to 121 grams/100 g BW or 222 to 481 g whole weight with an average of 93.0 :_5.4 g/100 3 BW (n - 8) or 326 1:20 g whole weight (n - 10). The weight of the glans was close to 1/3 that of the whole penis. Behavioral Influences Copulatory experience increased penis weights. Cohabitation with cycling females (69,75,99,l94) prior to testing as adults produced significantly higher penis weights than segregation with males or isolation. No differences in the number of penile papillae (PP) or penis weight (PW)(l95) was found between isolation and segregation. 218 The same increase was evident with repeated mating experience as adults. Sexual tests to at least one ejaculation twice a week increased PWs (75,194), but ejaculation once a week (75) or intromissions only (194) was ineffective. The PP were unchanged by intromissions only, physical stimulation of the penis, or handling (195). An effect of regular sexual experience on the PP was not established; the only related data demonstrated no difference between the PP of males that were maters and those that were non-maters (195). Furthermore, the number of PP were unaffected by section of the Pelvic or Pudendal nerves (150), indicating the maintenance of the papillae was not neurally determined. Castration The data showing the reduction of the penis following castration were extremely limited. The PP decreased to 52 of normal intact numbers by 21 days postcastration (32). The drop was exponential starting 6 days postcastration. No data provided a falloff pattern for the PW, but the minimal weight after prolonged castration was approximately 272 of the intact weight (111,112,113). Testosterone Testosterone data were available for a variety of treatments. With multiple injections, discriminations were possible between maintenance or recovery regimes and between free T and TP. The time course following a single injection of TP or TA was presented also. 219 Under maintenance conditions, the number of papillae were sus- tained at intact numbers by 75 ug of TP (32). With lower dosages, the decrease was dependent on both dosage and the length of treatment (32,49). For example, a 5 ug dose produced 70% of normal numbers with one week of injection, but by 28 days of injection the amount had dropped to 33% of normal. The recovery data for the PP were too limited to establish a dose response. A single study (177) reported normal PP numbers with 50 to 1000 ug TP. The model recovery dose response was established from the minimal values from the maintenance studies. Following a single injection of 10 mg TP, the PP rose to a maximum by 7 days after injection, remained high for two weeks, and drOpped to a mini- mum in another week (33). A single injection of 10 mg TA (phenylr acetate form) proved more effective than TP (33). PP number rose to normal numbers by 2 weeks postinjection, remained maximal for 3 weeks afterward, and dropped to about one-half normal after two more weeks. The effects on penis weight were available for recovery condi- tions. NOrmal intact weights were attained with between 200 and 500 ug of TP (113,177). On the other hand, more than 1000 ug of T was required to attain normal weights, and the degree of effect was related to the number of repeated days of injection (111,113). Comparison of the two forms of testosterone showed T 70% as effective as TP, considering both dosage and treatment time. 220 Estrogens The information on the various estrogens was insufficient for totally reliable predictions of changes due to dosage or days of injection, but some estimations were made. Free estradiol (E2) and estrone (E1)(l-5 ug) produced a significant increase in PW in long- term castrates (145). E1 and E2 tended to be slightly more effec- tive than estriol (E3), but none of the increases from the castrate level were large (r a 1.45 to 2.0). On the other hand, E3 at high dosage (60-180 1U) did tend to reduce the PW of intact males (106). In castrates, the higher dosages of E3 showed no effect on the PW (106). The two penile measures were not in agreement for the estrogen treatment. EB (1 ug) produced PWs near those of 200 ug TP after 20 days of recovery injections (181). The same EB treatment was substan- tially less than for the TP control for the PP (181). Furthermore, combination of high E2 with low TTP dosages produced no significant change, but reduced the effect of TTP on the PW (110,111) and the PP (177). Therefore, the three estrogens increased the PW over castrate weights, with E3 the lesser in effect. The increases, however, were minimal (approximately 352 of 200 ug TP response). EB was noticeably more effective on PWs than any of the free forms, but relatively ineffective on the PP. Combination of E2 with TP reduced the effect of the TP. As the dosage of E and TP were similar and the weights were halfway between the independent T and E effects, the two hormones were probably interacting competitively. 221 Androgen Influences A variety of androgens, other than testosterone, had effects on penis weight and papillae number. Both recovery and maintenance regimes were represented, although recovery was preeminent. The androgens will be described in order of effectiveness. DHT(P) could not be distinguished from TP of the same dosage. The equivalence held for maintenance (159,160) and recovery (12,72, 73,164,177) with 125 to 1000 ug dosages for the PP, and also held for PW recovery (145,164,177). Similarly, combinations of EB or TP with DHT(P) were equivalent to TP or DHT(P) alone. Recovery was the only reported regime. EB doses ranging from 0.5 to 167 ug combined with 125 to 1000 ug DHT(P) had PP numbers equivalent to TP (4-200 ug) or DHT(P) controls (11,73, 144). Control PWs were found with 500 ug DHT combined with E1, E2 (1 & 5 ug), or E3 (1-25 ug) (145). As might be expected, combina- tions of TP (4-200 ug) and DHT(P) effected no substantial change from DHT(P) alone on the PP (11,73,177) or PW (94,145,177). The same lack of change held for DHTP with BB-androstanediol (12). The effect on the PP of the remaining androgens was similar in a few cases. Androsterone (160,164) produced better than one-half the intact papillae number with 150 ug (160), and was equivalent to the intact at 1000 ug (164). At 150 ug, 3arandrostanediol, androstene- dione, and androstanedione (160) were very similar to androsterone under 35 days maintanance. 3p-androstanediol (160) was less effective than its isomer, and 19-hydroxyandrostenedione (160) and l9-hydroxy- testosterone (HTP)(159) were totally ineffective. HTP was ineffective 222 .even at 1800 ug. The androgen effects on penis weights were assessed under recov- ery and maintenance conditions. The data dealt with androstenedione (AEONE) and androsterone (AND). AND was on occasion altered to a digl_form and both forms were normally fat soluble or altered via estherization to a water soluble form. In some cases, a distinction could be made between dose responses under recovery and maintenance. In general, the order of effectiveness followed: AEONE, AND- diol, AEOL (androstenediol), and AND. AEONE (112) and AND-diol (108, 114,115) were similar under recovery with an oil vehicle. Both approached intact PWs in the 700 ug dosage range. AEOL (110,112) was intermediate. AND (107,114,115,l64) effects were the smallest, and its effectiveness was highly variable. According to calculated model relations, the dosage required to produce PWs midway between those of castrate and intact males at 20 days with injection were respectively: AEONE (midpt I 155 ug), AND-diol (mp I 51 ug), AEOL (mp I 590 ug), and AND (mp I 1132 ug). A maintenance regime required a lesser dosage to attain the same effect with 20 or more days of injection. The midpoint dosages under maintenance were mp I 31 ug for AND-diol (115) and mp I 603 ug for AND (115) in oil solution. The maintenance/recovery ratios were respectively; r I 0.61 & 0.53. The water solutions proved less effective than the fat (oil) solutions at the same dosage. The midpoint dosages calculated for the androgens were mp I 520 ug for AND-dial and mp I 1100 ug for AND under recovery conditions (114,115). Therefore, the relative effectiveness of the water solution, expressed as the inverse of the 223 water/fat ratio, were r I 0.10 & 0.54, respectively. Therefore, the relative ineffectiveness (PW) of androsterone was established compared to that of androstenedione and androstenediol. The addition of hydroxyl groups to produce androsterone-dial greatly improved the effectiveness of androsterone. A.maintenance regime required less androgen than recovery to produce equal effects. Finally, the water soluble forms of androsterone were at least one-half as effective as in oil solutions. Drugs Data were provided for the androgen analogue, fluoxymesterone (FM), the anti-androgens - cyproterone acetate (CYA) and flutamide (FL) - , and the anti-estrogens - HERFZS and CI-628. The only effects were produced by FM, CYA and FL. FM at 500 ug was able to bring castrate papillae numbers up to intact levels (36). CYA demonstrated some androgen properties by maintaining castrate (49,152) and EB (1 ug) castrate males at PP numbers midway between the intact and castrate males. However, CYA (10 mg) reduced the PP by one-half in males given TP replacement (49), but it had no effect on intact males (37). CYA only slightly reduced the PP maintained by DHT (1 mg), and was ineffective with EB plus DHT (152). PWs were not altered by CYA in castrate or EB treated males, but some depression of the DHT and DHT + EB highs was observed (152). However, FL (25 mg) did decrease TP sustained papillae and PWs, but it did not affect castrate males (180). The remaining drugs combined with T or TP did not alter the 224 testosterone maintenance of the penis. The number of PP were unaffected by 10 mg MER-25 (12). Neither MER or CI affected the PWs of castrates alone or with T (151). Synopsis The penis measures, the number of epidermal papillae (spines) or penis weight, usually agreed in response, but the papillae number was more sensitive to most variables. Several behavioral treatments altered the penis. Sexual experience increased PWs when experience was represented by cohabitation and repeated tests to ejaculation. Tests to intromission had no effect on either measure. The PP number was not affected by ejaculation tests, however. Possibly, the PP numbers were maximal in intact males with adequate testosterone. Severing nerves to the penile area had no effect on the PP. Androgens substantially affected the penis, but estrogens had only minimal influences. After six days of castration, the PP dropped to a 52 minimum and PWs fell to a 27% minimum. Testosterone returned both measures to intact levels. A 75 ug TP dosage main- tained the PP, but 200 to 500 ug TP was required for the PW; T was about 702 as effective as TP. Only minimal increases over castrate PWs were achieved with E1, E2 or E3; EB was more effective than the free E2. PP numbers were little affected by the estrogens, noticeably less than the PW. At high estrogen dosages in combination with T, and intermediate PW was seen. Other androgens brought the penis to intact condition. DHT(P) was equivalent to TP on both measures, and combinations of estrogen 225 or TP with DHT(P) were equivalent to the same dosage of DHT(P). The remaining androgens were less effective than DHT, requiring higher dosages to sustain intact penis structure. For PP number, the androgen effectiveness followed the decreasing order: androsterone, 3arandrostanediol, androstenedione, androstanedione, BB-androstanediol, and finally hydroxyandrostenedione and HTP, which were totally inef- fective. For PWs the order was: androsterone-d101, androstenedione, androstenediol, and androsterone. The maintenance conditions required a lesser dose to achieve the same PW values as recovery. The water soluble forms of androsterone proved less than half as effective as the oil soluble forms. FM produced PP numbers rivaling those of testosterone. Only CYA and FL were able to influence androgen action. CYA not only reduced the PP numbers of T or DHT treated males, but also increased those of castrate males. However, CYA did not substantially affect the PW. FL was more effective than CYA; it reduced TP supported PP to numbers equivalent to an untreated castrate male. MER-25 and 01-628 were totally ineffective. All the changes required time to develOp. Almost a week was necessary to initiate a rise or a fall from the start of treatment, regardless of the rate of increase to intact or fall to castrate values. This was a time course intermediate between changes occur- ring in hormone blood levels and behavioral measures. 226 6.8 Introduction to the Hormone Summaries The final three summaries are concerned with the sytemic blood hormone concentrations of Testosterone (T), Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH). The data were generated by radioimmunoassay (RIA), and the concentrations were expressed in 2g of hormone per ml_of serum (ng/ml). The systemic blood was taken from a variety of sources, that included: decapitation, the jugular vein, tail vein, abdominal aorta, or cardiac puncture. The most common source was via decapitation. No consistent differences in the blood concentrations for any of the hormones due to the blood sources could be seen. The model reports the hormone concentrations to give an indicator of the hormone level present in the rats when the behavior occurs and due to the variety of possible treatments, that may or may not affect the behavior. As described previously, the hormonal state strongly influences sexual behavior and penile structure. In the male, the primary hormone affecting the behavior is T. The produc- tion and secretion of T is controlled by LH and FSH, secreted by the pituitary gland. The concentrations of T feeds back, negatively, on the hypothalamus and pituitary and moderates the secretion of LH and FSH. Furthermore, in the body tissues, T can be converted directly to estradiol and DHT, and eventually to all of the minor androgens and es trogens . The model attempted to reflect the hormone interrelationships. lllthough the model was designed to have the hormone subprograms itifluence one another, they do not do so very effectively. The very 227 poor data available for the crucial linkages between the subprograms prevented an effective working relationship. The interaction of the hormone subprograms required two basic stages; the output of each hormone subprograms (e.g., FSH and LH) was a blood concentration, that had to be converted to an injection dosage to serve as an input to another hormone subprogram (e.g., T) or a behavioral or penile subprogram. The effects of the injection dosages of the three hormones were well supported. However, data on the conversion of blood levels to an apprOpri- ate dosage were sorely 1acking. Dose response data were no doubt developed in various laboratories, but rarely reported. Only one study was found for the relationship of T injection to blood level (139) or LH injection to plasma LH (12), and both studies provided questionable data. No dose response was available for FSH. The only exception was an excellent development of a dose response for plasma T in response to subcutaneous T implants (see T summary). Therefore, the hormone output of the model would be best considered as only an informative systemic indicator. A couple of issues need to be considered before beginning the summaries. First, the three hormones had circadian periodicities over a 24 hour day. Therefore, the concentration of all hormones varied with the time of day (TDN). These fluctuations, however, did not directly affect the behavior, which was maintained by a hormonal state over a period of days. All the hormonal effects were assessed, ‘as for the behaviors, with ratios of the hormone level of a treatment group compared to a control, usually intact or castrate males. In the case of variables with no definite control, such as the circadian 228 patterns, the samples were averaged across the range of the variable. For example, if a study took blood samples every two hours during the day, the average of the 12 data points would serve as the control value used to calculate the ratios for each sampled hour of the day. This provided the same circadian pattern, but as ratios rather than absolute blood concentrations. As far as the TDN variable was concerned, the model used a 12L:12D light cycle, so the dark period was from TDN of 0 to 12 and the light period was from a TDN of 12 to 24 or 0. The alternative 14L:10D cycle was converted for use in the model by proportionally stretching the dark hours and shrinking the light hours. As a point of reference, sexual testing and activity were best during a TDN of 4 to 6 hours. On the other hand, blood sampling occurred during the light period in the hormonal studies reporting a specific time. Finally, all the reference numbers presented in the hormone summaries refer to the separate hormone bibliography following the behavior bibliography. With these conditions in mind, the discussion of the effects of treatments on the hormone plasma levels proceeds. 6.9 Testosterone The systemic blood concentrations of testosterone (ng/ml) had negligible differences between the strains; their ranges all greatly loverlapped. The total range was 0.97 to 4.75 (5.58 - single outlier) ng/ml. The average of all normal adult male studies (n I 66) was 2.79 I1.8/ml. The concentration of T from the testicular vein was of the or- f testosterone. With a receptive female, T started to rise with the 232 introduction of the stimulus female at an average rate of 0.036 ng/ min. (69,72,108). The T rise reached a maximum, approximately twice the basal level, at 30 minutes or more into the test. When testing began after the male was left alone in the arena for 5 hours, the T level was already at the maximum for normal testing. However, with exposure to a receptive female, an added rise occurred to the same degree as described for males tested directly (69). The same rise occurred when the receptive female was present in the arena but the male was not allowed physical contact; however, T started to decrease earlier, at 30 minutes of testing (108). The T rise varied based on the nature of the sexual stimulus object and the males' sexual experience. No differences between sexually naive and experienced males was evident (71,72) for T rest- ing levels prior to testing. Following testing, naive T levels were lower than those for experienced males (naive/exp. r I 0.71) for all sexual objects (71,72). Other sexual objects produced differing effects on T. T response was compared with that for receptive females at least 20 minutes after completion of a sex test. For experienced males, the effect on T induced by a sexual object followed the descending order: nonreceptive female, no contact female (separated from male by screens), female odor alone, and a male stimulus (71,72). The male stimulus was totally ineffective. The timing of the T rise to alter- nate sexual objects was not clear. The nonreceptive female did not alter the T from resting level up to the first PEI (71), but the T ‘was elevated at 20 minutes posttest (72) for the nonreceptive female, 'near to the receptive female level. For sexually inexperienced males, 233 none of these stimulus objects elevated T (72). The initial rise in naive males either did not occur or T dropped back to normal levels by at least 20 minutes after testing. Other behavioral treatments produced effects on T. Shock pro- duced a 60% decrease in systemic T (10,47) up to 4 hours afterward. Shock or handling at an early age produced no effect on T when sampled later in life (49). The remaining behavioral variable, raising condition, had reported, contradictory results (33,56,107) and no effect was assumed. Castration Following castration, plasma testosterone decreased rapidly. The exponential decrease attained minimal levels (cast./intact r I 0.011 to 0.152) between 4 minutes and more than 24 hours (2,22, 50,51,52,68,ll6). The variability in the reported data made the establishment of a rate of decrease difficult. The better data (22,68,116), giving early measurements and short sampling intervals, indicated a rate of e-3°0.CASTH(ht3') as a compromise. The equation provided a minimal T level within two hours. Cryptorchidectomy produced only minor T decreases compared with castration. The minimal crypt/intact ratios ranged from 0.53 to 0.95 with an average of r I 0.79 (2,50,51,52,82). 234 Testosterone Only one study (139), unfortunately, provided systemic T concentrations for T injections of castrate males. Plasma T at 20 hours after the seventh daily injection approximated intact levels at a 50 ug/lOO g BW (125 ug/rat) dosage. T 9 to 10 times intacts was reported with 100 ug/100 g EN (250 ug) or more. When the same dosages were injected into intact males a rise was indicated at the 50 ug/lOO g BW (150 ug) dosage and a five fold increase at 100 ug/lOO g BW (300 ug). As these rapid T changes with increased dosage were decidedly nonlinear and the data limited (n I 5 males/group), the relationship must be considered unreliable. Data were available on both castrate and intact males given silas- tic implants. The plasma T of castrated adults remained relatively constant over 36 days with 5 to 15 mm implants (123). Intact T concen- trations were attained with the 60 mm T implant (23,90,96,122,123), and the rise from 2 to 60 mm was linear. Differences due to age were not clearly established (122) after 50 days of age. The rate of increase was approximately 0.045 ng/ml for each 1 mm of T implant. Implants given intact males displayed the same rate of T increase as the castrates (8). However, the T levels were reportedly depressed at dosages of 20 mm or less (implant surface area was 10 times the length), and substantial increase was reported at 400 mm as compared with the next lower dose of 40 mm. The plasma T due to the TC (cyprionate) form was equivalent to the free T (8). With TP implants, the rate of increase due to dosage was doubled. With TP, the plasma T was depressed below the intact with 10 mm or less. 235 Estrogen Estradiol effectively reduced the plasma T to at least castrate levels when injected into intact males. With multiple days of injection (7 days), EB produced minimal and usually undetectable, levels of T with more than 1.0 ug (21,137). Free E2 required at least 10 ug to accomplish the same T depression (32). The course of the T depression following injection of intact males was also observed. EB at 50 ug or more produced the maximum T depression by 24 hours after either a single (136) or multiple (days) of injection (21,134). 0n the other hand, E2 produced maximal de- pression in the range of 3 hours postinjection, and T returned to intact levels by 24 hours after injection of 100 to 500 ug E2 (21). A comparison of the model exponents for dosage indicated a dose of EB was ten-fold more effective than the same dose of E2. Simi- larly, E2 lasted a shorter time in the systemic circulation. E2 was ineffective by 24 hours after injection, while EB was still maximally effective at least to 24 hours. LH and FSH Luteinizing Hormone (LH) produced substantial increases in the level of plasma T of intact males. T rose to almost 14 times normal intact levels with 10 ug/lOO 3 BW of LH or more. Thereafter, the level of T stayed on a plateau (91,92,93,100,101). The initial rise was exponential. No evidence was given for an age interaction (93,100,101). 236 The T time course following the LH injection (30 ug/lOO g BW) had a definite pattern, but the two reporting studies-varied some on the actual parameters. One study reported a peak at 90 minutes postin- jection (92), and the other at 60 minutes (101). The peak amplitudes differed also. Following the peak, a gradual return to normal levels was indicated. The two studies were of differing strains and age, but as no effects of dosage due to strain or age were indicated, none was assumed for the time course. The two patterns were averaged, and the maximum level set by the dosage equation(s). When BB (100 ug) was combined with LH, the plasma T was inter- mediate between the independent response to each hormone (91). A 1 to 3 ug LH dose was sufficient to counteract the effect of EB and returned T to intact levels. However, even with 100 ug LH, EB was capable of holding the LH induced rise to one-half its normal in- crease; the maximum T levels were almost three times intact levels. Contrary to the plasma T increase to a peak at 60 to 90 minutes postinjection with LH injections of FSH (2.5-100 ug/lOO g BW) produced no alteration of T (30,31,92). The lack of effect held for either multiple of single injection(s) and for young and adult males. Human Chorionic Gonadotropin (HCG) HCG produced substantial increases in plasma T. The T response to increasing dosage of HCG followed a logarithmic curve, at least up to 6 IU/lOO g BW (47 IU/rat)(5,54). The T rise began between 0.10 and 0.75 IU and increased to approximately 7.5 times the untreated T levels with 35 IU HCG. Old male T (24-26 mos.) rose to the same 237 level as younger males (3-12 mos.)(54). But because the vehicle control T was significantly lower, the relative increase for old males was far larger. After an HCG injection, plasma T rose exponentially to a maximum between 120 and 180 minutes postinjection (l8,54,88,108). The falloff after reaching maximal levels was far more gradual and linear (54). The time necessary to return to normal levels was unavailable. The time course for the old males (54) was approxi- mately the same, but the relative rise over time was exaggerated by the initial low T value. The actual patterns were about the same. Hypophysectomy (HX) Hypophysectomy resulted in a plasma T drop to a minimum within one day (136). The average HX/intact ratio for the l to 21.5 days following was r I 0.11 (6,53,55,115,136). The injection of LH (5 & 25 ug)(6,115) to HX males increased T over HX levels. FSH (20 ug) combined with 5 ug LH returned T to intact levels (115). However, FSH had no effect on HX males alone or with the high LH dose (25 ug). The 25 ug LH alone brought T to above intact level. Several other hormones were capable of altering T levels of HX males. Prolactin (200 ug) produced only minor increases, but when it was combined with 5 ug LH, a synergistic increase to intact T levels was observed (53). Pregnenolone (2 mg), l7-Hydroxy-pregnenolone, progesterone, and l7-Hydroxyprogesterone (2 mg) failed to significantly affect the HX T levels (55). 238 Endocrine Glands Adrenalectomy reduced T levels only under circumscribed condi- tions. A significant T decrease was reported (67) during the early hours of the light period, but not during the dark period, of the light cycle at weeks after adrenalectomy. T decreased (r I 0.30) between 0.5 and 2 hours immediately following adrenalectomy (116). The combination of adrenalectomy with castration caused adrenalectomy effects only within the first 24 hours. Adx + Cast produced T levels one-half those of castration alone, until after 12 hours, when no difference from castration alone could be detected (42,116). Both thyroidectomy and pinealectomy affected the plasma T con- centrations. Thyroidectomy produced a one-half decrease in T (17). Pinealectomy, on the other hand, resulted in a three fold T increase (76). Drugs The only data on anti-androgens or anti-estrogens was for the anti-androgen, Flutamide (FL). FL produced substantial T increases over repeated days of treatment of intact males (125). The induced T increase peaked by 5 days of treatment and decreased somewhat there- after. However, 5-fold levels were still reported after 30 days of treatment. The maximum level was 7-fold that of the intact. As the FL effect was probably mediated via hypothalamic feedback, no effects of combinations of FL and T, TP or DHT treatments were found (68,124). 239 Starvation Starvation produced an approximate one-third decrease in T level (59,60). A decrease was evident only after a full day or longer . without food. Synopsis The systemic plasma levels of testosterone were altered by a variety of intrinsic conditions and treatments. Changes were seen due to daily patterns, seasonal changes, and behavioral treatments. The most obvious aspect of the circadian T patterns was their variability, and the resultant lack of agreement among the reporting studies, regardless of strain. The average daily pattern was damped to low amplitude changes. However, an average peak was observed in both the light and dark periods and the major nadir was during the dark. Furthermore, exposure to constant light increased T, and constant dark decreased T, overall. A definite interaction existed between season and age. The T surge early in the year (Feb.-Mar.) occurred only in young males, males born during the late fall and winter months. Males sampled during the summer produced a significant 60 Day age peak and fell to adult levels, while the winter males had a gradual and steady rise to adult levels with their peak around 90-100 Days of age. T concen- trations began to fall off by 9-10 months of age and dropped to a minimum by 14-15 months. The introduction of the male to the sexual test arena produced a 240 rise in T. These effects occurred only in sexually experienced males, making these effects "anticipatory” in nature. A T elevation occurred always with an introduction of a receptive female. The elevation occurred even on top of the initially high T levels induced by prolonged exposure to the arena. Partial female stimuli (nonrecep- tive, no contact, or odor only) produced only partial increases in T, and no change was produced with the introduction of another male. Furthermore, shock during testing decreased T, but the condition of raising produced results too ambiguous to draw conclusions. The majority of hormonal treatments produced changes in plasma T. Castration produced near nondetectable T levels within two hours. Cryptorchid males had lowered T, but only to a small degree. The use of T implants resulted in a linear dose response in castrates and intact males. Data were presented for T injections, but they were less than adequate and further confused by changes following injec- tion. Implant studies established the doubled effectiveness of TP over T and the equivalence of T and TC. Estradiol effectively reduced T to castrate levels with more than 1.0 ug EB and 10 ug E2. ‘Following an injection of E2, minimal depressions were attained in the range of 3 hours following injection, and returned to intact level by 24 hours. EB had a sustained effec- tiveness well beyond 24 hours. 0f the nongonadal hormones, LH produced the most dramatic effects on plasma T. LH injection resulted in an almost 14 fold T increase by 60 to 90 minutes postinjection. The T level decreased thereafter. The combination of EB with LH produced intermediate results; LH prevented the EB induced decreases, or EB ameliorated the 241 LH rise. FSH, conversely, had no effect on the plasma T. HCG produced T increases slightly less than those of LH, with a maximum at 120 to 180 minutes postinjection. Hypophysectomy effected a drOp in plasma T to very low levels. However, the T levels tended to be slightly higher than for castra- tion. Adrenalectomy produced a decreased T just following surgery and later during the light period, but effects due to adrenalectomy and castration were distiguishable only within the first 24 hours postcastration. Thyroidectomy decreased T somewhat, and pinealectomy increased it. Pregnenolone, progesterone, and their hydroxylated forms were ineffective. Flutamide produced a T increase in intact males over a period of days to levels rivaling those of HCG. Starvation resulted in some T depression after a day of deprivation. 6.10 Luteinizing Hormone The concentration of Luteinizing Hormone (LH), expressed in ng/ml serum, in the systemic circulation was influenced by a variety of variables. Intrinsically, the LH concentration followed daily circadian rhythms and changes over the males' lifetime. The largest body of knowledge concerned a variety of hormonal manipulations resulting in LH blood level changes. However, initially the effects due to the intrinsic and behavioral variables were considered. The normal, intact, untreated male LH levels were established as averages of all studies, using one data point from each study.’ The Inale strain determined the base LH level. The Holtzman strain had the lower LH concentration of 10.2 113.7 ng/ml (E :_SE, n I 10 242 studies). The Wistar males were the next higher at 24.4;: 5.7 ng/ml (n I 16). The Long-Evans and Sprague-Dawley males were equivalent at 36.2;: 7.3 ng/ml (n I 7) and 36.3:: 8.6 ng/ml (n I 31), respectively. The highest strain group was an assorted one; the Mixed strain LH was 50.1 i 8.0 ng/ml (n I 12). The average of all strains was 32.5 i 4.2 ng/ml (n I 76). A great deal of variation in the reported LH concen- trations occurred within the strains. The ranges of the different strains all overlapped substantially (total range I 0.5 - 93.7 ng/ml). However, as the strain group SEs with their means did not overlap, inherent strain differences were assumed. A good deal of the varia- tion could be accounted for by the LH-RIA assay done in different laboratories, the time of day of blood collection, and the age and condition of the male rats. Daily Patterns Large changes in LH through the day were consistently in evidence All the males were on a l4L:lOD light/dark cycle with the lights turned on between 4 AM and 7:30 AM. The cyclic patterns during the 24 hours varied in the times the peaks and nadirs occurred. Almost all rats demonstrated one or more LH peak(s)(73,89), but they occurred at dif- ferent hours. Consequently, the averages of a group of males (4-10 males) also shift among the hours from one study to the next, even within the same strain. The average of all studies utilizing a given strain established a general pattern for modelling purposes, which reduced the individual peak heights and nadir depths. The Sprague-Dawley studies reported peaks at TDN (lights were 243 off for TDN I 0-10 hrs. and on for TDN I 10-24 hrs.) of about 2 (39), 5 (40), and 12 to 15 (80,116,120) hours. The strain average showed a major peak at TDN I 13 and a minor peak at TDN I 5, with the principle nadir at TDN I 21. The average curve for the Wistar studies (19,28, 86) indicated a major peak at TDN I 5.5 and a minor peak at TDN I 17.5, with a nadir at TDN I 23. The Wistar and CD (67) pattern was similar to that for the SD males. The three strains were combined for one general curve, that had a major peak at TDN I 13, a minor peak at TDN I 5, and the nadir at about TDN I 21. The Holtzmann pattern was different. The peaks of the individual studies (58,133,143) were scattered to the later part of the light period and between TDN I 2 and 5. A very consistent nadir occurred at TDN I 9 to 10.5 in all studies. The average curve had a high peak at TDN I 4 and a nadir at about TDN I 10, at lights-on. Only a gradual increase in LH over the light period was indicated. The SD-W pattern was approximated by a cosine function with a period of 7.5 hours for TDN I 3 to 16. The Holtzmann pattern was approximated by a sine function with periods of 15 hours (TDN I 0-8) and 9 hours (TDN I 8-12). The remainder of the patterns were approximated linearly. The peak and nadir for the Holtzmanns was substantially greater than any for the other strains, due to the averaging effect of the combined strains. Furthermore, the cyclic changes, regardless of their nature, were eliminated when the males were castrated (80,143). This castration effect on the cycle was undoubtedly due to the higher LH output following castration. 244 Age LH levels were different at earlier ages than as adults, but the differences were not consistent among the strains. The Sprague- Dawley (ll,34,35,8l,104) and Wistar (20,100,129) demonstrated a high variability at ages less than 55 Days. On the average, a gradual but small increase with decreasing age, at least to about 40 days of age, was present. The remaining strains; Holtzmann (97,98,102), Long-Evans (122), and Ivanovac (51); demonstrated a large sigmoid increase from 40 Days up to the adult level (100 Days). These changes were significant. During the adult period (90-190 Days), no consistent changes were evident (23,88,122). M°°k.EEH2lf (88) males intimated a LH rise during the months of spring. Past 190 days of age, LH tended to gradually decrease (88,121). The LH concentration fell to approxi- mately one-third the adult levels by 600 Days (almost 20 months). Behavioral Effects Systemic LH changed in response to sexual behavior testing and to different sexual stimulus objects. When the receptive female was placed in the test arena with the male, the male's LH concentration rose rapidly to a high point (Trt./basal level r I 2.59), and then gradually decreased over 60 minutes (69,70,72). The same response occurred in castrate males given T implants (10-25 mm T), but no change occurred in castrate males given either no T or a 5 mm T implant (70). 245 Furthermore, males left alone for 5 hours in the arena, prior to the female's introduction, showed the same LH release patterns as males without the prior exposure (69). However, LH had risen by the start of the test, probably due to the 10 minute adaptation period or the anticipation of the female (72). In terms of the sexual behavior, LH had reached a maximum by the first intromission, and decreased during the ensuing behavior (71). When a nonreceptive female was substituted for the receptive female, the same LH response pattern was observed, but the increase was somewhat less (71), although not significantly. The mating LH tended to be higher in sexually naive males than males given prior sexual experience (71,72). However, the divergence due to sexual experience did not occur when the female was nonrecep- tive (72). The mating LH rise also occurred when the sexual stimulus was a receptive female separated from the male by a mesh screen (no contact) or exposure to female odor only in the test arena (72), regardless of the sexual experience. When the sexual object was another male, a smaller LH increase occurred for experienced males, and no increase was seen with naive males (72). The caging conditions after weaning had some effect on LH. The pituitary LH content (107) of cohabitant males was statistically lower than that for segregate or isolate males. A very similar LH rise occurred in the presence of a receptive female regardless of the caging condition. Furthermore, some indication had been given (126) that if males are tested during the hours of light, no LH rise occurred. 246 Castration and Cryptorchidism LH rose rapidly in response to castration. A plateau was attained by 24 hours postcastration (9,117,142). When the strains; Holtzmann (2,9,46,78,142), Sprague-Dawley (3,116,118,144), Wistar (15,132), Long-Evans (ll7),'and Mixed (1,138); were compared, no consistent differences could be seen, primarily due to the wide variation in the LH. The LH rise following castration was biphasic. After the initial plateau (cast/intact r I 8.30) was attained by the first day postcastration, another LH rise started at approximately 7 days postcastration. The secondary rise attained a plateau by about 14 days postcastration (r I 13.8). However, the second rise was more exponential, so the approach to the plateau was more gradual than for the initial rise. No interaction between the castration rise and age was indicated (ll,50,51,57). Some of the ratios for ages of 60 Days or less tended to be higher, but the data were also more variable at these ages. Cryptorchidism had a far lesser effect on LH. Cryptorchid males produced LH levels a little more than double the intact level (2,50, 51,102,129,l40). The plateau was attained after approximately 4 days following surgery. LH rose to about the same level regardless of age, even though the intact age value differed (50,51). 247 Testosterone The majority of the testosterone treatments involved injections (T and TP) for l to 7 days of castrate males. The LH ratios had the castration level as the control, so if effects of testosterone were evident, the LH ratio decreased from the castration high. Because no consistent differences could be seen among the strains or between the recovery and maintenance regimes, these were combined for discussion. TP (ll,24,43,44,66,85,98,105,109,128,138) depressed the LH some- what more than the free T (ll9,127,128,l32,139). The T? depression occurred at a lower dosage; approximately 30 ug/rat more was required to begin the T depression. The decrease in LH was exponential with a higher rate for TP than T. If the intact/cast. ratio was assumed as r I 0.120, as predicted by the castration equations (average reported value was r I 0.114 (n I lO-studies)), the TP dosage of 408 ug and the T dosage of 636 ug forced LH to intact levels. With a subcutaneous silastic T implant, a rapid decrease in LH occurred with increasing millimeters of implant greater than the 2 mm length (23,90,96,122). Comparing the rate exponents of the implant and TP or T injection the relative doses became 18 ug TP or 27 ug T for each mm of the T implant. A further method utilized was intravenous infusion of T (4.2 - 918 ug/day) over two to three days. The dosage required to obtain the same depression of castrate LH as injection was far lower. The dose response exponents indicated an effectiveness of infusion ten times that of injection (62). The rapidity of the LH response to a single injection of TTP was 248 observed. With a single injection of 200 ug (62) or 2 mg (132) of T, the LH levels approached intact levels by 8 hours postinjection. The decrease in LH was exponential. After 24 hours, the LH was near castrate levels again. No data were available for TP injections prior to 24 hours. However, the TP induced decrease was sustained far longer than for T. TP attained its maximum depression by 48 hours postinjection, and for doses less than 2 mg, began to return to castrate levels by 72 hours (62,66). The time course for the return to castrate levels did not appear affected by dosage, although the dosage did determine the degree of depression and the rate of return to castrate LH values after 48 hours. With 500 ug TP or less, castrate levels were attained by 72 hours (62,66). A 1.0 mg TP dose partially depressed and 2.0 mg fully depressed the LH at 72 hours (66). When intact males were injected with T, LH was depressed. With at least 25 ug T/lOO g BW (approx. 75 ug/rat/day), LH was decreased to less than one-third the intact level, often reaching nondetectable levels (29,139). The depression was accomplished within 5 hours post- injection with 2 mg T (132). However, the data were too scanty to es- tablish any pattern of LH decrease in the intact males treated with T. Testosterone effectively overcame the effects of castration. The injection of TP was more effective than free T, both in dosage and prolongation of effect. A single injection of T lasted less than one day, but TP remained effective for at least 2 days. Each mm length of a T implant was equivalent to approximately 27 ug of T injected per day, and infusion was ten times as effective as injection. With ‘a sufficiently high dosage, TTP depressed LH below intact levels in 249 castrate males, as it depressed LH in intact males to below detectable levels. Estrogen Data on LH were available for estradiol, free (E2) and benzoate (EB) forms, and estrone (E1). Injections were given at castration or under recovery conditions. Intact males were also treated. Dose response data were available, as well as the LH time course following a single injection. Distinct differences were seen between E2 and EB. EB injected into castrate males on repeated days produced decreases in the cas- trate LH with more than 0.4 ug, regardless of the treatment regime (44,66,83,128,138). With increasing dosage, the LH decrease was exponential, dropping to intact levels (av. intact r I 0.192 (n I 5 studies)) by about 2.5 ug EB. Although the free E2 dose response was also exponential, a LH depression was noted only after more than 1.5 ug was injected (128). Intact levels (r I 0.30) were attained in the range of 8 to 10 ug (32,128). However, the data were too highly variable and meager to place great weight on these limits. In general, EB was far more effective than E2 injections when given over 5 or more days. Estrone followed a dose response similar to E2 from 0.03 to 30.0 ug/lOO g BW (127), and was only slightly less effective than E2. When EB was given to intact males, the results were equivocal. The EB/intact ratios were found on either side of r I 1.0 across the dosages of 0.05 to 100 ug EB. No dose response pattern was observable 250 (21,84,9l,137). The same was indicated for E2 (132,136). The time course of the LH decrease following a single injection of EB was similar to that for TP. LH fell to a minimum by 24 hours postinjection, and remained so to beyond 48 hours, when at least 5.0 ug EB was used. The EB castrates returned to their castrate LH levels by 72 hours (66). With very large dosages (SO-100 ug EB), LH was decreased within 2 hours postinjection (132). As occurred for T, the E2 males' LH returned to castrate level by 24 hours after injec- tion (136). Repeated sampling over 1 to 24 hours after a 50 ug EB injection into intact males (134) showed no change from intact levels, although another study (136), with less data, reported a drop within one hour (500 ug E2). Substantially, EB was longer lasting and more potent with repeated injections than free E2. Estrone was only somewhat less effective than E2. These effects were only reliable in castrate males. In intact males, the data varied so greatly a further decrease in LH could not be assumed. Estrogen with Testosterone When EB was combined with TP, effects were observed at the higher dosages of both. The independent LH depressions due to EB or TP alone tended to average when combined (44). This competitive effect was observable easily at dosages greater than 0.25 ug/lOO g BW (1.0 ug/rat) of EB and 15 ug/lOO 3 BW (60 ug/rat) of TP (44,128). iHowever, within the dosage ranges used (0.01-2.5 ug EB & 0.5-120 ug 'TP), the overriding effect was that of estrogen, so the ratios of 251 effect were closer to the EB averages than predicted by the average of the EB and TP alone ratios. A closer approximation to a pure average might have occurred if the larger, more common dosages of TP were combined with the EB dosages utilized here. Androgens DHT(P) was effective in depressing castrate LE to intact levels. LH began to decrease with around 10 ug DHT(P) with 5 or more days of repeated injections. The rate of LH decrease due to increasing dos- age was greater for DHTP (138) than DHT (127,130). DHTP injections depressed LH to intact levels with more than 20 ug and DHT injections with more than 100 ug. The repeated days of DHTP injection pushed LH to its minimal level between 3 and 5 days of injection (138). Several other androgens suppressed the castrate LH. 3abandro- stanediol was the most effective of the remaining androgens (127, 145). Its isomer, 3B-androstanediol was only about a tenth as effective (127,145). Androstenedione followed 3a-androstanediol in degree of effectiveness. Slightly less effective was 4-androstene- diol, and its alternative isomer 5-androstenediol was about a tenth as effective. DHEA and epiandrosterone were rather ineffective, and androstanedione was totally ineffective, even with 2000 ug (127). Therefore, in descending order of effectiveness in depressing the castrate LH, we had: DHTP, DHT, 3a-androstanediol, androstenedione, 4-androstanediol, 3B-androstanediol, 5-androstenediol, DHEA, epiandrosterone, and androstanedione. 252 Endocrine Gland Effects Adrenalectomy did not alter LH levels in intact males (46,67, 116). Males castrated and adrenalectomized concurrently had a delayed LH rise compared with castration alone. The delay was of the order of 24 hours (116). No effect on the castrate LH was seen at later times postsurgery (44,48,116). Prolactin (150 ug) was unable to produce any change in adrenalectomized intact males (48). Thyroidectomy produced no statistically significant changes in LH _ within intact males (17,40). However, several days following thyroid- ectomy in castrate males, LH was significantly increased (r I l.34)(l7). Insufficient data were provided to establish a time course for the LH falloff after hypophysectomy (l) and to establish LH levels following injections of LH (12). Pinealectomy had no effect on castrate LH levels (131). Miscellaneous Treatments An insignificant decrease in the castrate LH was reported for injection of 2.5 mg of progesterone (16,132). A mild reduction was indicated in intact males (132). In addition, the progesterone dose did not alter any of the effects of EB (14,41,43) or TP (14,41). There was no effect of hydroxyprogesterone or pregnandione (29). LH increased when Flutamide (25 mg) was given to intact males, but it did not reach castrate levels (125). FL did not affect the castrate LH level, showing no estrogenic or androgenic prOperties of FL. FL did not have a substantial effect on TP (100 ug) injected 253 castrates. However, another study (68) reported a significant interference of FL (6.25 mg) with the lowering of LH due to a 30 mm T implant over a period of 10 days, and a very similar interference with DHT (10 mm implant) was reported (68). Starvation consistently reduced LH in intact males (r I 0.71), when starvation was extended at least 2 days (59,60,6l,ll4). No change was induced by starvation in castrate males (60,61,113,1l4). Synapsis LH was very responsive to the intrinsic variables of age and time of day. The timing of LH peaks or nadirs during a 24 hour day were highly variable among individuals, strains, and studies. Holtzmann males, on the average, had a major peak during the middle of the dark period and a nadir around the time of lights-on. The remaining strains had peaks during the middle of the dark period and the beginning of the light period, and a nadir near the end of the light period. These cyclic changes were variations about the LH strain averages. The daily cycles disappeared in castrate males. LH increased from 40 days of age to adult levels, except for the Sprague-Dawley and Wistar males, that had a gradual and small LH decrease to adult levels. With progression into old age, LH decreased in a gradual linear fashion. LH rose rapidly as soon as the male was placed in the testing arena, and rose to a maximum by the first minute of the sexual behavior test. LH fell gradually during the ongoing testing. Naive males tended to produce higher LH levels than sexually experienced 254 males. The mating LH rise occurred even with no contact females or estrous odors alone. The rise was less when the sexual stimulus was another male. Cohabiting males had lower LH levels compared with other caging conditions. Castration produced a biphasic increase in LH, that attained maximal levels by two weeks after castration. LH also rose after cryptorchidectomy, but not to the extent of the castrate males. Testosterone and estrogen depressed the castrate LH to intact levels and below. TP was more effective than free T, and EB was more effective than free E2. About 400 ug of TP and over 600 ug of T was required to reach intact level. T was effective for a little less than one day, while TP was effective over almost three days following a single injection. Testosterone was effective regardless of the delivery method - injection, implant, or infusion -, and it produced decreases in LH when given to intact males. EB produced intact levels of LH with about 2.5 ug, and E2 . required 8 to 10 ug to attain the same effect. The duration of effect was very similar between estradiol and testosterone; E2 lasted about the same duration as T, and EB was like that of TP. Estrone was only slightly less effective than E2. Combination of EB and TP resulted in an averaging of their independent effects, a competitive interaction. Among the remaining androgens, DHT(P), androstanediol and androstenedione were the more effective in depressing the castrate LH, and DHEA or epiandrosterone were the least effective, with androstanedione totally ineffective. Adrenalectomy had little effect on LH. It only delayed the LH 255 rise following castration. Thyroidectomy produced LH increases only in castrated males, and pinealectomy was ineffective. Data on several other hormonal treatments were available. Progesterone and pregnandione had no significant effect on castrated or intact males. Flutamide interfered with the operation of the pituitary-gonadal feedback. Finally, starvation depressed LH in- intact males, but was ineffective in altering castrate levels. 6.11 Follicle Stimulating Hormone The systemic blood concentration of Follicle Stimulating Hormone (FSH) was expressed in ng/ml of plasma. The average FSH concentra- tions for normal intact males presented no substantial differences among strains. The variation about the individual averages for each strain all overlapped, requiring the pooling of all strains. The overall FSH average was 402 i 23 ng/ml (3(- 1 SE, n I 54 studies). Long-Evans and Sprague-Dawley males tended to be the lowest, and Holtzmann males tended to be the highest. These normal levels varied based on the time of blood sampling for RIA and the males' age. Daily Cycles Cyclic changes were evident over the 24 hour day, but the cycles varied among strains. Differences were observed between Holtzmann, Sprague-Dawley, and Wistar males. The variation among studies was high; some reported no pattern, some one peak, and others two peaks. All studies utilized a 14L:10D photoperiod. 256 Holtzmann males demonstrated FSH peaks consistently at TDN I 6 to 8, during the dark period, and nadirs around the time of light-off (TDN I 20-2 hrs.)(58,64,133,143). The average curve had a peak (r I 1.25) at TDN I 8 and nadirs at TDN I 22 (r I 0.875) and 2 (r I 0.92). The FSH peaks and nadirs for Sprague-Dawleys were similar to the Holtzmann but less consistent. Two studies registered no significant pattern (40,116). The two remaining studies (67,120) had peaks in the dark period, but not at the same hours, and nadirs at both lights-on (TONI 10) and near lights-off (TDN I l). The average curve had a gradually developing peak at approximately TDN I 15.5 hrs. (r I 0.92), near the middle of the light period. Wistar males (19,86) had reported peaks between TDN I 17 and 19.5, midway into the light period, and nadirs on either side of lights-off. The average peak was subtantial (r I 1.41), but no consistent nadir was evident. As individual males had single, double, or triple peaks over the 24 hours that varied in both time of occurrence and amplitude, a random averaging of different groups of males might have produced similar differences in the average patterns, that would not be de- pendent on strain. This would be a reasonable basis for assuming an equivalence between the Holtzmann and Sprague-Dawley males. However, the Wistars were so divergent, with the major peak in the light period not found for the others, that they should be considered different. 257 Age Differences among the strain averages were also seen for the effects of age on FSH. All strains produced a pattern of decreasing FSH from 35 days of age to an adult level, attained by 60 to 70 days of age. The major difference among strains was the initial (35 Days) FSH level and the resultant rate of decrease to adult level. The maximal values at A I 35 provided a comparison of strains The highest maximal young/adult ratio occurred for the Wistar males (r I 3.64)(20,94,100,121,129). The Ivanovac (r I 2.10)(50,51,52), Sprague-Dawley (r I l.90)(26,34,35,8l,104), and Holtzmann (r I 1.48) (63,97,98,102) fell below the Wistars in descending order. The comparatively high response from the Wistar males was, at least in part, due to the pronounced peak seen previously during the middle of the light period; of the studies reporting the time of blood collec- tion, all sampled in the middle or end of the light period. A gradual decrease with increasing age was indicated at least to 240 days of age (26). Behavioral Treatments The behavioral treatments produced no significant changes in FSH, totally unlike the increases in the LH. No FSH changes were observed over 120 minutes of sexual testing (4,69,72,126)- The same held for males alone in an arena for 5 hours (4.69)- 258 Castration & Cryptorchidism Castration produced large increases in the systemic FSH. The increase was two stage, as occurred with LH. FSH rose rapidly immediately following castration (116) and leveled at a four fold concentration by 6 days postcastration. This plateau was sustained until an average of 28 days postcastration (range was 10-42 days post- castration). The second FSH rise was more gradual than the first, and it attained a level almost seven times that of the intact male. All strains demonstrated a similar postcastration rise, with some amplitude dissimilarities. Holtzmann (2,45,78) and Wistar (15,129,140) males had the higher cast./intact ratios, followed by the Sprague- Dawleys (3,116,144) and others (1,138). No consistent interaction was seen with age (50,51). Cryptorchid males also demonstrated an FSH rise following the operation. The rise was linear and gradual, attaining an apparent maximum after 7 to 8 weeks (r I 2.75). The cryptorchid level was only a little more than a third of the castrate level (2,102,129, 140). An interaction between age and cryptorchidism was not established (50,51). Testosterone The changes in FSH due to testosterone were established through averages of TTP/cast. ratios, where the controls were castrate males. Testosterone treatments were segregated by delivery method (injection, implant, or infusion), treatment regime (maintenance or recovery), 259 testosterone form (free T or TP), and comparisons of dosage or time course following an injection. No data were available for testos- terone treatment of intact males. The maintenance dosage data were the most prevalent. TP in multiple injections (44,98,128,138) produced initial FSH decreases by 20 ug doses and attained an approximation of intact levels around 200 ug TP. Injections of T resulted in FSH decreases at about the same dose level as TP, initially, but the rate of decrease over increasing dosage was far slower (127,139). T attained intact levels only with dosages greater than 1000 ug. A similar divergence in effectiveness between T and TP resulted under recovery conditions. An initial FSH decrease was seen only after 120 ug of T or TP, noticeably more than for the maintenance condition. In addition, the T and TP forms differed, as before, in the rate of decrease over increasing dosage. TP doses of over 1100 ug were extrapolated to produce intact FSH levels (98,128). T dos- ages in the range of 6000 ug were expected to attain intact FSH con- centrations (128,130). With TP, some increased effect was indicated with repeated injections over extended periods (> 7 days)(128). The greater effectiveness of TP could be explained by its greater longevity in the circulation. A single injection of TP pro- duced an FSH depression that was maximal by 48 hours postinjection (66). When the single TP dose was greater than 1.0 mg, the depres- sion was extended to at least 72 hours (43,66). Lower dosages returned to castrate levels by 72 hours (66). The actual degree of depression was dose dependent. T tended to return to castrate levels after 24 hours postinjection (29,62,145), although at dosages greater 260 than 1.0 mg, an immediate return was questionable. The data on alternate delivery systems were scant. A silastic implant containing T produced no change in castrate FSH with a dosage of 4 mm or less (96), and dosages of 40 mm or more depressed FSH to intact levels (90). These data were inadequate for a dose response curve. Infusion of T intravenously produced an FSH depression with be- tween 5 and 20 ug/day (62). Intact levels were attained with around 200 ug/day. Some further depression occurred with infusion on adjacent days, and FSH returned to castrate levels by 24 hours after infusion, even with dosages up to 1000 ug (62). In summary, TP was far more effective than T in terms of the amount required to depress castrate FSH to intact levels. TP remain- ed in the systemic circulation more than twice as long as T. A main- tenance regime produced depressions with a lesser dosage of T or TP than a recovery regime. T implants were as effective in depressing FSH as injection, and infusion was more effective than T injection for the same dosage; both returned to castrate levels by 24 hours afterward. Estrogen Information existed for estradiol, primarily EB, and estrone. Injections were given to both castrate and intact males. However, the data were insufficient for the establishment of differences in dosage between maintenance and recovery regimes. Maintenance was the primary delivery schedule. In castrate males, EB effectively depressed FSH (44,83,128,138). 261 FSH began to drop with EB dosages between 0.025 and 0.8 ug/day with multiple days of injection; the average was 0.24 ug/day. Intact levels were attained by 4 to 50 ug EB, depending on the particular study. The response to free E2 was similar to EB, but higher dosages of E2 were indicated (127,128) for the same effect; EB was several times more effective. Estrone (127) was approximately one-half as effective as E2. Under recovery conditions, the maximal depression was less than under maintenance (128). EB and E2 were able to depress the FSH of intact males in addition. EB depressed the intact FSH to about one-half its normal concentration with 5 to 10 ug (84,137). Again, E2 proved less effec- tive. More than 1.0 ug of E2 was required to cause any depression, and the one-half level was not attained even with 100 ug (32). The pattern of FSH depression in intact or castrate males was unavailable. No significant change from the control level was observed when blood was taken 18 or more hours after an injection. Therefore, all FSH decreases were based on the dose responses, with estradiol showing depressions of FSH to intact levels in castrate males, although to a lesser extent under recovery conditions, and to the r I 0.50 level in intact males. E1 was only about half as effective as E2. Androgens DHT(P) given to castrate males depressed FSH to intact levels. DHT produced intact FSH levels with dosages approaching 1000 ug (127), but DHTP produced the same depression by 80 ug (138), when both forms 262 were injected on multiple days (5-7 days) under a maintenance regime. However, under "recovery" (DPC-5) conditions, DHT depressions were less. Intact levels were approached but not attained with as much as 6500 ug (130). The recovery depression was initiated at approximately the same dosage 65200 ug) as maintenance, but the rate of falloff did not produce the same degree of depression. Apparently, with a single injection (2 mg), FSH returned to control levels within 24 hours (145), and no cumulative effect over repeated days of injection was observed (138) over 10 days of treatment with DHTP (5 ug). Other minor androgens proved less effective than DHT in castrate males (127). The depression resulting from 3a-androstanediol was only slightly less than for DHT, but that for androstenediol was about one-quarter of the androstanediol depression at 1000 ug. With dosages up to 2000 ug, androstenedione, 3p-androstanediol, 5-androstenediol, DHEA, androstanedione, and epiandrosterone were ineffective. Hormone Combinations The effects of testosterone and estrogen tended to average when the two were combined. At lower doses of T? (0.05-30.0 ug/lOO g BW) and EB (0.0025-0.5 ug/lOO 3 BW), the average of the independent hor- mone treatments fit the FSH depression in castrate males very well (44). The average held for 400 ug TP with 10 ug EB (128). The results with a single injection of 1.0 mg TP with 1 ug EB (66) in castrate males and a single injection of 1.5 mg TP with 20 ug EB (26) in intact males were less consistent. 263 Estradiol was combined with several other hormones (29). No substantial effects were observed with E2 + DHT in intact males. Synergism was evident when E2 (50 ug) was combined with hydroxypro- gesterone (5 mg) or pregnandione (2.73 mg) in intact males; the treatment ratio (r I 0.68) was significantly different from the normal intact FSH. However, in castrate males, hydroxyprogesterone and pregnandione were capable of depressing FSH, and that depression was only insig- nificantly increased by combination with E2 or DHT (1.5 mg). Proges- terone (2.5 mg) did not alter the response to EB (14,41) or T? (41) in intacts or castrates. Endocrine Glands Adrenalectomy produced a small FSH decrease (r I 0.77) between 12 and 24 hours after surgery, and thereafter, in intact males (48, 116). When castration and adrenalectomy were combined the castrate rise was inhibited; however, after 24 hours postsurgery (116), no effect of adrenalectomy could be distinguished (44,48,116). Thyroidectomy produced a significant FSH decrease (17). How- ever, intact males thyroidectomized at 40 days of age and sampled 6 weeks later showed no FSH changes (40). In castrate males, thyroid- ectomy significantly increased (r I 1.85) FSH at 15 days after thyroidectomy (l7). Pinealectomy had no effect in castrate males (131). Further- more, insufficient data (1) were supplied to establish the FSH falloff after hypophysectomy. 264 Starvation The removal of food from intact males resulted in a gradually decreasing FSH concentration (59,60,61,1l4). The FSH decrease attained a minimum by 3 days (r I 0.69) of starvation. However, in castrate males, starvation tended to increase the castration levels (r - 1.30)(60,6l,113,114). Synopsis The patterns of change in FSH blood concentrations closely followed those of LH with only a few exceptions. Substantial differ- ences among strains were not evident for FSH, which were evident for LH. FSH showed changes throughout the day. Holtzmann and Sprague- Dawley males had peaks during the dark hours and a nadir around the time of lights-off. Wistar males diverged noticeably due to a mid- light period peak and a nadir around lights-off. FSH was maximal around 35 days of age and fell gradually to adult levels. Thereafter, a gradual decrease was indicated into old age. Unlike the LH rise with exposure to a sexually receptive female in the test arena, FSH was not altered in response to any behavioral treatments. Both FSH and LH demonstrated the two stage rise following castra- tion. The subdued cryptorchid rise was also present. Testosterone and estrogen depressed FSH in both castrate and intact males. The longer lasting forms (TP and EB) required a lesser dosage to produce the same effects as the free T or E2 with multiple days of injection. 265 The infusion method was more effective than injection. E1 was less effective than E2 in stimulating FSH decreases. Both testosterone and estrogen depressed FSH to intact levels in castrates with suffi- cient dosages, and estrogen produced depressions to half levels in intact males. Recovery conditions tended to retard the effectiveness of these steroids compared with the maintenance regime. DHT(P) was the most effective in reducing castrate FSH compared with androgens other than testosterone. DHTP proved more effective than DHT, and again recovery retarded the effectiveness of either. The effect of 3a-androstanediol was slightly less than DHT, and androstenediol was even less so. The remaining androgens were ineffective. The combined effects of TP and EB averaged. A synergistic effect was observed in intact males for E2 with hydroxyprogesterone or pregnandione. Hydroxyprogesterone and pregnandione had their own independent decreasing effects in castrate males. Progesterone appeared ineffective in combination with gonadal steroids. Adrenalectomy produced a small decrease in FSH in intact males, and only inhibited the postcastration rise. Thyroidectomy effected an FSH decrease in adult intact males, but produced an added rise in castrate males. Pinealectomy was ineffective. Starvation managed a one-third decrease of FSH in intact males and a small rise in castrates, a change similar to thyroidectomy. Chapter 7 Theoretical Considerations 7.1 Introduction The model of male sexual behavior described herein addressed the relationships of the intrinsic, environmental, sensory, and hormonal variables to the resultant male sexual behavior, defined by the eight behavioral measures (IL,IF,EL,PEI,EF,PE,PI,PM). The penile and hor- monal measures served only a secondary role. When taken as a whole or subdivided into variable classes, these relationships shed some light on the interrelation of the behavioral measures, as well as on the current behavioral theories and the models derived from them. If the current theoretical mechanisms adequately explained the behavior, they would be influenced, with a good deal of consistency, by the classes of variables affecting the behavior. Furthermore, these influences might be organized into model components, added to future models, that would more fully demonstrate male sexual behavr ior. Any redundancy among the measures reflecting the behavioral mechanisms would appear as strong correlations between the measures across a wide range of variables. The relationships between the behavioral measures provided information about the sufficiency of the theoretical mechanisms and about the potential of viewing male behav- ior as a single integrated composite. 266 267 7.2 Theoretical and Modelling Implications One of the best and more current discussions of the state of the theoretic developed for male rat sexual behavior was provided by Sachs and Barfield (172). Mbst of the theoretical mechanisms de- scribed were utilized by recent computer models (78,197). The dif- ferent mechanisms would be expected to differentially affect the behav- ioral measures, because several mechanisms appeared necessary to fully describe male rat behavior. The effects of the range of variables incorporated in this model should reflect the differential involvement in the behavior of the currently developed theoretical mechanisms. Knowledge of the relations of input (treatment) variables to the mechanisms would then further the development of model components dealing with intrinsic, sensory, penile, and hormonal factors influencing the mechanisms directly controlling the behavior. All the effects evident in this descriptive model would need to be represented in any future complete model of male behavior. The explanatory mechanisms or internal components of later models should produce results consistent with this empirical model. Several conceptual mechanisms underlying male sexual behavior were described by Sachs and Barfield (172). The mechanisms could be paraphrased as follows: * A. An "arousal" mechanism It postulates an increase in a CNS activity bringing the male to approach the female and initiate or reinitiate mounting and intromission. B. An intromission threshold It is a level of excitation that is sufficient for E. 268 intromission (I) behavior to occur. Mechanisms controlling copulation - the control of the time 1. 2. repeated Is leading to an ejaculation (E). The Quantal Hypothesis The immediate, stepped excitatory increments resulting from each intromission that triggers an E when suffi- cient excitation (the E theshold) is attained. The Nonquantal Hypothesis It is a refinement of the quantal hypothesis to account for the enforced interval effect. It assumes an additive excitation with each intromission, but the individual excitation increments develop with time following each I, up to a maximum that dissipates over time if the next I is delayed. The Temporal Hypothesis The controlling element is the time following the first I. The threshold for E in an internally set duration, with the repeated Is sustaining the excita- tion level established with the first I. An E gating system This allows the release of the ejaculation behavior upon the receipt of appropriate signal(s). active postejaculatory inhibitory mechanism The mechanism prevents the initiation of further sexual behavior for a period following each E. The inhibition after a given interval (absolute refractory phase) begins to weaken and interact with the arousal mechanism, al- lowing a gradual return (relative refactory phase) to the start of the next ejaculatory series. A Satiety mechanism It is an inhibitory mechanism that builds in strength gradually, lengthening consecutive ELs and PEIs and culminating in the cessation of sexual behavior. (Sexual satiety was often referred to as sexual exhaustion.) 269 These mechanisms should differentially affect the behavioral measures. The arousal mechanism would be expected to primarily affect the ML, IL and PEI, that measure the latencies to the reinitiation of sexual behavior. The ML would probably be the better measure of "pure" arousal, i.e., the inclination to approach and mount the female. However, the ML suffered from the lack of a sufficient data base, that was the primary reason for not including it in the empirical model. The ML could serve a useful purpose, but not as an isolated measure. A ML/IL ratio would help decipher changes in the relation- ship of the underlying arousal mechanism to the ability to attain intromission. A wide discrepancy between the ML and IL, a low ratio, would indicate no change in arousal but some interference with intromission (penile stimulation), as occurred with the PNX. Higher ratios would show good correspondence between the two, signifying both were affected similarly and penile input was not the important factor. Under the latter condition, longer than ”normal” ILs or MLs would demonstrate some reduction in arousal. Because of the lack of ML data, the IL had to serve as the indicator of arousal mechanism changes, when not confounded by manipulations of penile sensation. The PEI also had an initiation component, the relative refactory phase, that comprised the last third of the PEI. As the PEI terminated at the first intromission, it also suffered from the confounding of arousal and penile input. The copulatory mechanism(s), those controlling the intromission sequence to ejaculation, might or might not be a single independent system; however, the EL and IF would be the affected measures. The 270 copulatory mechanism(s) would probably interact with spacing mechan- isms or inhibitory mechanisms, that extend copulation and eventually eliminate it. Copulation was totally inhibited during the PEI and a satiety mechanism elongated copulation with increasing ejaculatory series to the point of behavioral termination. Most of the mechanisms were represented in computer models as internal components. Freeman and McFarland (78) included components for the arousal mechanism, I and E thresholds, E gating, and quantal elements. Toates and O'Rourke (197) incorporated the arousal component, I and E thresholds, PEI inhibition, and satiety effects. These models provided behavioral outputs very near those of normal untreated males. However, neither the degree or nature of the interactions among the theoretical mechanisms was clearly established. The explanation of some behavioral observations has, so far, remained elusive. The observations included the fewer Is to E (lower IF) in the second series compared with the first, the same for the lower ELZ, the differential lengthening of the absolute and relative refractory phases of the PEI with increasing series, the dissociation of the IF from the inter-intromission interval, and the inverse relation of the IF and the intromission duration in response to enforced 1013. Furthermore, the effects of the variety of impinging stimulus and hormonal states on these mechanisms was not established. Were some mechanisms affected and others not by the stimulus and hormone variables, or were they differentially changed? A discussion of the effects on the measures of behavior, reflecting the operation of the theoretical mechanisms, was aided by clumping variables and their 271 effects into potential model components. The effects of the variables present in the model suggested three major new components. A sensory integrator would decide the weighting of incoming sensory stimuli for sexual behavior, hopefully giving qualitative and quantitative information for the operation of the behavioral mechanisms. Although the penis provided sensory in- formation, the information would be treated by a separate component, primarily because the penis was influenced by a variety of androgens and no direct evidence was available for hormones affecting the functions of a sensory integrator directly. The third and final component was for hormone effects, a component difficult to define. Hormonal effects might not independently affect the behavioral mechanisms, but might serve as state functions within the behavioral and penile components. A comparison of the effects of the modelled input variables upon the behavioral measures demonstrated differential influences. Not all nor the same behavioral measures were affected by different treatment variables. The differential effect supported the establish- ment of the three hypothetical components. Furthermore, the results indicated which mechanisms would be affected by what variables or components. The connections of the postulated components to the behavioral mechanisms will be considered in turn, based on the effects of the relevant variables upon the behavioral measures. For greater detail concerning the individual effects of the variables, reference to the sections on each behavioral and penile measure and the listing for the direction of effects for each variable and measure in Appendix C is suggested. 272 Sensory Integrator The first hypothetical component, the sensory integrator, organ- izes and condenses all incoming stimuli to an appropriate value or values to be utilized by components controlling the behavior. The integrator deals with the five senses, and operates independently from penile sensation. The exact, intimate workings of the sensory integrator remain unclear, as the experimental support of the "workings" is insufficient. However, a few glimmerings are avail- able. Experimentally, the sensory data results from two different types of manipulation, removal of the sensory organ and alteration of the stimuli available to the male. The removal of a sensory organ produced some change in all the behavioral measures. The effects of the different sensory oblations are detailed in Table 7.1 in terms of their experimental/control-sham group ratios for each measure during the first series. The behavioral measure most affected was the IL, as the high E/C ratios showed. The EL was a close second. The IF and PEI were hardly influenced by the treatments. Decreases in the EF and PE were also evident. Specifically, olfactory bulbectomy (OBX) occasioned more change than blinding or sectioning the fifth nerve. Deafness was not tested directly, although it has been inadvertently induced by some surgical procedures. Furthermore, Beach (14) reported the removal of more than one sense organ eliminated all sexual behavior. The effects on the IL were exaggerated in inexperienced males (OBX r I 3.41 & Blind r I 6.00). The oblation results reflected upon the mechanisms controlling 273 Table 7.1 * The E/C Ratios For Sensory Oblations of Sexually Experienced Males. Oblations IL IF EL PEI EF PE PI PM osx* 1.76 0.86 3.60 1.25 0.62 0.57 0.77 0.77 Blind 1.00 1.00 1.86 0.86 0.88 0.42 0.62 0.62 5th NX 4.76 1.00 - - - 0.50 0.83 1.00 * Any of the Experimental/Control group (E/C) ratios above 0.85 and below 1.20 were assumed to show no effect, as the usual range for statistically significant ratios was outside these values for most studies. Only when several studies were averaged, like for the OBX, did ratios within that range demonstrate significance. 274 copulation and arousal. The copulatory mechanism(s), represented by the EL and IF, was altered; the efficiency of the temporal element was retarded. The effect on the arousal mechanism was not as clear. The PEI was not strongly affected, although the IL was. A definite lengthening of both would have been more conclusive. The ML rather than the IL would have been the better measure of arousal. Perhaps the ML would have remained unchanged like the PEI, demonstrating no arousal effect. However, the ML data (85,168,185) were too poor to draw conclusions, and no reliable intra-study come parison of the ML and IL was available. A decrease in the effects on the IL with sexual experience suggested the inclusion of a learning element in the sensory integrator. The satiety mechanism was probably stimulated by sensory oblation. Reduction of sensory input tended to decrease the EF and definitely decreased the PE and PI. Whether the satiety and copula- tory mechanisms interact was Open to question, but the reduction in sexual activity was evident; the males stopped earlier and fewer responded. No evidence for a hormonal influence on the sensory integrator existed, due to a paucity of experimental effort. Larsson (137) indicated that neither high levels of TP nor LH with FSH produced any further behavioral change in the OBX males. However, Larsson was the only experimenter to use a combined treatment and report it. In addition, no strong theoretical reasons could be found for assuming hormones had a direct effect on sensory integration. When the sensory organs were left intact, the quality of the stimuli presented to the male in a sexual test arena influenced the 275 measures of behavior. The stimuli were categorized into those pertaining immediately to the female and those to the general environment. The female stimuli included the degree of sexual receptivity displayed, the activity of the female, and the substitution of other sexual objects as the focus for copulation. A fully receptive, estrus female was required for the display of normal levels of male sexual behavior. Few males would attain intromission with active nonreceptive females, but they did mount regularly. However, the reduction in female stimuli were confounded with changes in the female's behavior - nonreceptive females would often repulse the male. Similar low levels of behavior occurred when other males, guinea pigs, or an immobilized receptive female were presented as sexual objects. VAGX (receptive female with a closed vaginal opening) females produced a reduction in the IF and the EL in the reduced number of males responding. The ML, IL, and PEI were unaffected. The interference with vaginal intromission apparently influenced the c0pulatory mechanism only, or the experimental VAGX selected for those males performing more rapidly and with fewer Is. Substitution of a new stimulus female at sexual satiety reinitiated copulation, but did not substantially alter the behavioral measures relative to the last complete series. Classical conditioning paradigms using access to a receptive female as the unconditioned stimulus showed no consistent patterns among the measures. The best assessment was that stimuli other than those from a normal receptive female reduced the efficiency of copulation. The blood hormonal changes due to exposure to various sexual 276 objects were more sensitive to the differing stimuli. LH and testos- terone levels increased during sexual testing with various sexual objects. The height of the LH surge at the start of testing discrim- inated among the stimuli. Obviously, the receptive female produced the highest LH peak, but the nonreceptive female also produced a high peak. The peak was lower for a receptive female physically separated from the male (no-contact) and for the presence of estrus female odor alone. A male stimulus or handling had even lower levels. The LH peak changes indicated arousal changes, because the surge occurred at the very beginning of testing, before the first intromission. Similar results were obtained for testosterone. The T rises in the presence of a receptive, nonreceptive, or a no-contact female were equivalent. However, after 40 minutes, the increased T levels were not sustained with the nonreceptive and no-contact female. The presence of female odor did not induce as high a T increase and a male stimulus was even less effective. Therefore, some discrimination of the stimulus content occurred, which then stimulated a relative LH release, inducing a later secre- tion of testosterone. The relative stimulus intensity of the sexual object would be: the receptive female (100%), nonreceptive female (90-1002), no-contact female (80%), female odor only (702), and another male (45%), based on rough estimates of relative changes in LH and T. These could be the values passed to the arousal mechanism. The environmental stimuli tested were a hodge-podge, but they indicated some sensory integrator functions. The "excitatory” stimuli, i.e. group testing, observation of a copulating pair prior 277 to testing, handling, and moderate electric shock, had differing effects. The most consistent was an EL decrease in all cases. The EF was increased, in most cases the IF decreased (group Ts, handling), and the PEI decreased (handling, shock). The IL was inconsistent. In addition, the group tests and handling produced effects primarily in old males; the younger males were usually unaffected. Apparently, the copulatory mechanism(s) were stimulated to greater effectiveness by the "excitatory" stimuli, resulting in decreases in both IF and EL. Theoretically, the excitation (quantal) for each intromission was increased, the time necessary for E (temr poral) was reduced, the E threshold was lowered, or a combination of the three were possibilities. The influence of the satiety mechanism was reduced, as indicated by the increased EF and PE. If the satiety mechanism operated directly or indirectly on the other behavioral mechanisms, an improvement in the IF and EL, as well as a reduction of the PEI and IL representing the arousal component would be expec- ted; however, the measures representing the satiety and copulatory mechanisms were more strongly influenced than those for the arousal mechanism. The excitatory changes had a learned element. Males entrained to a shock avoidance paradigm - linked to copulation with the female - showed the same changes in behavior as males given shock during testing. However, if the trained males were tested in a novel arena, the effects of the learned shock excitation disappeared. The behavioral changes were self-induced, based on an ”expectation" of shock. The learning element was further supported by the reduction in the IL of naive males given repeated sexual experience. The other 278 measures were not altered by experience. Sexual experience seemed to affect only the arousal mechanism. When noxious stimuli were presented, such as high painful shock levels or a loud noise during testing, the reverse of the excitatory changes were seen. The IF and EL were increased along with the IL and PEI; EF and PE decreased. High shock stimulation was intense enough to nearly eliminate intromission. Sexual arousal was depressed, and satiety stimulated; the efficiency of the copulatory mechanism(s) was reduced. The possible interaction of the satiety mechanism with the others was again indicated. Electroconvulsive shock (ECS) had different results. ECS in- creased the IL and PEI and decreased the IF and EL, depressing arousal and stimulating copulatory mechanisms. The ECS, however, was not a manipulation of stimuli, but an over-stimulation of all cortical areas. The effect was not consistent with the removal of one sensory modality. In general, the hypothetical sensory integrator would have two major elements. The effects of sense organ removal would result in quantitative decreases in the output of the component, with a total elimination of output for multiple sense loss. This decreased output would produce debilitating effects on the behavioral mechanisms; the result would be an elongated IL and EL, a retardation of the copulatory mechanism, a decreased EF and PE, accelerating satiety, and a tendency toward increased arousal (IL,PEI). The effects of impinging stimuli were more qualitative in nature. Considering both behavioral and LH and T effects, the stimuli represented by a receptive female were Optimal. The lesser stimuli; non-receptive female, no-contact female, female odor, and a male, in descending order; were discriminated well 279 by LH and T rises, but poorly by behavioral measures. The effects of the environmental stimuli could be expressed as an inverted U-shaped function - low to moderate stimulus intensities, as the excitatory stimuli, stimulated sexual behavior, but more intense stimuli, as the noxious stimuli, retarded the behavior. In addition, the weighting of stimuli should be alterable due to repeated exposure to a stimu- lus; learned associations would particularly influence the arousal mechanism. Penile Component An independent penile component was separated from the sensory integrator for two basic reasons; the penis was very sensitive to hormonal conditions, unlike the integrator, and the sensory integra- tor dealt with stimuli received from the males' environment. The effects of neural output from the penis were assessed by sectioning nerves innervating the penis and by penile anesthesia. Several androgens were capable of supporting the penile structure. Sectioning the Pudendal or Dorsal Penile nerves produced increases in the IL and EL. The IF was unaffected, and the PEI increase as questionable. The BF and PE showed large decreases. Apparently, PNX had little or no effect on arousal, which was expected as neural feedback for the penis would occur primarily during intromission. This was supported by the basic lack of change in the PEI and ML (118,142,150,l98 & Vomachka, Berg: 2223). The IL increase was evidently due not to the arousal stimulated approach and mounting but to the reduced ability to attain or perceive intromission. 280 The result of reduced input to the copulatory mechanism, the increased EL, was to extend the temporal element. As the IF was unchanged, but the time required for each I was increased, a quantal explanation was unlikely. The strong PNX reduction of the PE, but little effect on the PI, indicated the lack of penile sensory input to the CNS might prevent the attainment of the E threshold (possibly set to a higher level) or the trigger of an E gate in most males. The satiety mechanism was strongly stimulated, as the EF fell to a minimum ratio of r I 0.18. As the EF was reduced five fold and the EL increased three fold, some interaction between the mechanisms controlling capulation and satiety was again indicated. However, the satiety effects did not appear to directly affect the arousal mechanism. Penile anesthesia complemented the PNX results, but anesthesia was not a particularly good experimental treatment. Anesthesia eliminated ejaculation and most intromissions, but as with PNX, no change occurred in the ML (83). The presence of androgen was required for maintenance of the penile papillae, that maximize stimulation of the sensory receptors on the penis. Testosterone, DHT, androstenediol, androstenedione, androstanedione, androstanediol, and the nonsteroidal androgen, FM, all influenced the papillae. TP, DHT, and FM, however, were fully effective. PNX did not influence the plasma hormone levels. When the hormonal support was removed by castration, the reduction of sensory penile information was not immediate. The papillae remained normal for about 6.5 days, and then regressed over a period of two weeks. The return to normal condition with injections of the 281 stronger androgens was almost three to four times slower than the castration regression. Therefore, the penile component would reflect the gradual change in output with hormonal treatments. However, the penis was not the only component affected by hormones. Hormone Component? The utility of an independent hormone component was question- able. Time lags, measured in days, were required for the gradual development of hormone effects. Nonhormonal behavioral and penile changes and implied influences of the controlling mechanisms developed over substantially shorter time periods. Because of the time dis- crepancies, hormonal effects might be treated better as state func- tions within each of the behavioral, sensory, or penile components. A hormonal state assumes no hormone induced change during each individual sexual test. The state would be capable of shifts only between tests. In addition to the conceptual problem, the scattered available information needed for the model relationships was a problem. Often, the time courses for the development of hormone effects were not reported, only the test averages. Furthermore, dose responses within the submaximal dosage ranges were rarely reported. For example, the data on TP injection had very few studies (28,32,49,60,l77) with multiple doses, with at least one dose less than 100 ug - the approximate minimum dosage for normal behavior maintenance. The studies did not provide the time courses for the doses for any of the frequency or latency measures. The combination of multiple lower 282 dosage and time course were reported (32,49,177) for the PE and PI, only. The remaining problem was one of analysis. When a hormone was removed, the number of males responding decreased over time, so fewer and fewer males provided values for the behavioral measure averages with increasing time. These averages were compared with pretest scores for the entire group or with the averages from concurrent control groups. In neither case was any account taken for changes in the experimental male group means due to the selection for males with greater sensitivity to the hormone treatment or greater behav- ioral endurance. This was of particular import when the measure under consideration, e.g., the PEI or IF, demonstrated their major changes just before the cessation of behavior. Analysis procedures need not be changed, as the experimental regimens leave few options, but the reporting of the pretest scores of the males that were the last to cease responding - those that most influenced the establishment of the pattern of change over time should be included in articles. Regardless of the difficulties, general hormonal effects could be loosely grouped into those involving CNS action and those primar- ily involving peripheral action. The theory that testosterone aromatized to estradiol, that acted centrally to influence behavior, and testosterone was converted to DHT and other androgens, that act peripherally to maintain penile and spinal structure or activity supporting sexual behavior, was the basis for the categorization. The generalities were consistent with the differential effects of the variety of hormones included in the model and their influence on the postulated behavioral mechanisms. 283 Hormone comparisons rather distinctly separated the behavioral measures believed to govern the copulatory and arousal mechanism. Changes in the IL and PEI were consistent with no change in the IF and EL; the inverse held as well. The effects on the EF, represen- ting a satiety mechanism, were also discriminative. Castration demonstrated the hormonal influences on the satiety mechanism. The EF and IL were the most sensitive to the lack of testicular hormone. measure comparisons were made using a half-point value, that was the value for the variable under consideration, when the E/C ratio was half way between, in this case, the intact and long-term castrate ratios. The half-point (HP) for CAST for both EF and the IL was approximately 9 days. Nine days was also the HP for the penile papillae, suggesting that penile input restrained the satiety mechanism. The remaining behavioral measures produced much longer HPs: respectively; 44, 56, & 70 days for the PEI, EL & IF; the PE-PI HP as 14 to 15 days. Apparently, the critical influence was the output from the penis, which decreased rapidly with time following castration. The penile sensory output reduction made the attainment of intromission more difficult, elongating the IL, and effecting a similar dr0p in the number of males capable of attaining I or E, thereby lowering the PE, PI and EF. Little evidence of effects on the arousal mechanism was observed, because the PEI was affected only when most males ceased c0pulating. The IL was too closely tied to the penile output for con- elusive assumption of arousal effects, and the data for the ML were scanty and inconclusive. The EL effects were more likely linked with the declining ability to attain I than copulatory mechanism changes, 284 because the IF remained stable up to the cessation of behavior. Androgens other than testosterone acted primarily at peripheral sites. DHT, androstenediol, androstenedione, and FM caused increases in the IL and PEI, but did not affect the IF or EL. These androgens had demonstrated effects on the penis, and DHT had a definite mainte- nance effect on the spinal reflexes (94). Therefore, the androgens maintained the penile output necessary for the sequencing of sexual behavior controlled by the copulatory mechanisms, at least to the point of behavioral cessation. The androgens were not capable of maintaining the activity of the arousal mechanism. Estradiol produced effects Opposite those of the androgens. Estradiol increased the IF and EL, and had little or no effect on the IL and PEI, in spite of extremely low EFs and PEs. As estradiol was believed to act centrally, and had no effect on penile tissue, penile output was drastically reduced and the capulatory mechanisms were not sustained. Estradiol did appear to maintain the arousal mechanism, that does not require penile information. An effect of estradiol on the satiety mechanism was unassumable, as the sexual behavior was severely curtailed (see EF and PE summaries). The E threshold may have been raised so high that E could not be attained, or the E gating may have been blocked. Probably, the I threshold was also raised, as well as, possible retardation of quantal and/or temporal elements may have occurred. Therefore, estradiol could adequately support the arousal, but was insufficient for nominal copulatory mechanism operation. When the hormones could be segregated by central and peripheral operation, as with EB or DHT, distinct differences occurred among 285 the hypothesized mechanisms. However, when hormones had both central and peripheral activity, such as testosterone or hormone combinations like the DHT and EB combination, all clarity of effect disappeared. With the injection of testosterone, all measures were affected. The IF was influenced the least, but all measures attained an approximate of normal intact response between 50 and 100 ug TP. The penile papillae were more sensitive to TP than the behavioral measures. However, clear differentiation among the measures was not possible. A similarly Opaque picture developed with combinations of estradiol and DHT(P). The available dosage ranges produced either approximately normal intact responses (usually 200 ug DHT) or discrepant results. The IL and IF were not affected; the PEI had a questionable increase with EB, but not the E2 form, and EL decreased with E2 but not with EB. The differential effects of the hormones supported the central and peripheral distinctions; the hormones could act to influence CNS function or the sensory output from the penis. DHT and some of the minor androgens affected the peripheral structures, primarily, resulting in the maintenance of the operation of the copulatory mechanisms, but not the arousal mechanism. Estradiol, acting only centrally, maintained the arousal mechanism, but not the copulatory mechanisms. Single hormones, such as T, and hormone combinations, such as EB and DHT, that act both centrally and peripherally, resulted in no differential measure-mechanism effects. This did not imply the mechanisms controlling behavior were located either in the CNS, penis or spinal cord, but that the 286 hormones maintained the activity of tissues, neural or otherwise, that support the activity of the proposed mechanisms or components. The explicit connections between the penile, sensory, hormonal, and behavioral elements influencing or controlling the ongoing sexual behavior remained to be fully established. Synopsis Although the current development of theoretical mechanisms for the control of male sexual behavior do not explain all aspects of sexual behavior, they are sufficient to demonstrate relatively normal behavior when modelled. On the other hand, the intrinsic, stimulus, sensory, behavioral and hormonal variables influencing sexual behavior have not been systematically merged into the current theory or models. Components, such as a sensory integrator and penile component, and hormonal elements fill that void (see figure 7.1). Because the IF and EL reflect the operation of copulatory mech- anisms, the ML-IL and PEI reflect the arousal mechanism, and the PE-PI and especially the EF reflect a satiety mechanism, the connections of the new components to behavioral mechanisms can be indicated. In the sensory integrator, the quantal elimination of sensory input by sensory organ oblations retarded the Operation of copulatory mechanisms, particularly the temporal aspect, possibly retarded the arousal mechanism, and stimulated the satiety mechanism. Learning elements were required, at least, for the arousal connec- tion, and two or more oblations zeroed the integrator, eliminating the behavior. The stimuli representative of the sexual object .mEmacmnoms may com: wounded mmcmno mo coavomnad may mpmoavca woman one .msmanmsomz Hmnoa>mnmm dam .hpmdvmm .Hmwzon< mop op macmsmam no mpcmcomsoo mafinmm dam .hnomcmm .msassapm .ocoanom mo madnmcoapmamm one H.m mnswam + # 338 m uaonmmhse a IIIIIIJ, daonmmnne H I n HmHOQEmB economsoo + Hosanna I madcmm 287 .zoms HmH0H>m£mm ammondc< coggmmo b cmmonpmm IIIIII. smdcmsom: monosuom + mvmapmm Houmnmmch knomcom — Hm>oemm - _ oncom Emazmsoo: I I Hmmson< 33:35 .8: P 335qu swam #953 aficoacofiém $0030 xom IL, 288 presented a gradation from a fully receptive female to another male, which influenced arousal and probably indirectly showed rapid elimination of copulation mechanism activity with stimulus divergence from the receptive female. The environmental stimuli demonstrated an inverted U-shaped relationship; moderate, excitatory stimuli stimulated the capulatory mechanisms and retarded satiety, and more intense, noxious stimuli accomplished the reverse. These stimuli had little effect on an arousal mechanism, and a definite learning element was present. The reduction of output from the penile component, due to PNX or anesthesia, had little effect on arousal, but retarded the copulatory mechanisms, primarily the temporal element and E threshold or E gate, and strongly stimulated the satiety mechanism. Unlike the sensory integrator, the penile component required hormonal support. A grad- ual decrease, over days, in penile output occurred with elimination of androgen support and returned from zero levels with androgen addition. The increase with androgen supported recovery was three to four times slower than the regression decrease following castration. Whether hormonal effects are handled by a separate component or as elements of the behavioral mechanisms, the results supported separation by central and peripheral effect. The IL and EF, repre- senting the arousal and satiety mechanisms, and penile papillae were the most sensitive to testicular hormone elimination at castration. DHT and other minor androgens, acting primarily at peripheral sites, maintained normal operation of cOpulatory mechanisms but not the arousal mechanism. Estradiol, acting centrally, produced the opposite result; it maintained the arousal mechanism and not the 289 copulatory mechanisms. Hormones, such as T, and combinations, such as EB and DHT, with both central and peripheral activity, usually maintained normal function of all mechanisms, and at low dosages all mechanisms were affected just prior to behavioral cessation. The state of hormonal maintenance of the copulatory mechanisms would override all influences of the sensory integrator and penile components. 7.3 A Composite Male Sexual Behavior Measure ? A composite male sexual behavior measure, that indicated an effect if any one of the separate measures demonstrated an effect, could not be clearly established. Based on the association among the male measures, the significance of each measure could be implied relative to the copulatory behavior as a whole. The relative number of effects demonstrated by each measure and the correlations between. the measures also aided the search for the composite. Several general formulations were utilized to make comparisons among the behavioral and penile measures. The first formulation was a measure by measure correlation analysis using Kendall's Coefficient of Rank Correlation (182), presented in Table 7.2. The correlated values were the maximum or minimum E/C ratio values attained in the model over specified variable ranges for each measure. The second general measure was a compilation of the reported occurrence of experimental effect and its direction (see Appendix C). To compare measures, counts of the number of times one measure showed a change and another changed in the same or opposite direction for the same 290 treatment variable were taken. The total number of measure to measure comparisons, i.e., with data to make comparison, were presented in Table 7.3. In Table 7.4, the number of times two measures were affected in the same and opposite directions were listed. Table 7.5 showed the ratio of the majority group, either same or opposite direction change, to the total possible comparison number (Table 7.3). The final formulation, a sensitivity indicator (Table 7.6), utilized counts within each behavioral measure, rather than between. The number of reported effects were given as counts and expressed as a ratio to the total number of variables with data support. They were organized by variable class. The basic assumption of this compilation was simplistic - the more treatment conditions capable of inducing a measure change, regardless of its direction, the more sensitive that measure was. The relative number of effects was consistent across the different variable classes, with the one exception of the drug variables. Effects reported as statistically nonsignificant (p>.05) were counted as no change. If the behavioral mechanisms were valid, a composite could be composed of one measure representing each theoretical mechanism. Either the IF or EL, the ML (or IL) or PEI, and the EF or PE would be possibles. The IF was the best candidate for elimination from conten- tion due to the redundancy. The IF was the least responsive to all treatments - it had the lowest sensitivity ratios (Table 7.6), it did not correlate with any of the other behavioral measures (Table 7.2 - the IF was the only measure without statistically significant correlations), and it was the least consistent measure (Table 7.4 - 291 Table 7 .2 Correlations Between the Behavioral Measures. Measure IL , IF EL PEI EF IF ”.06 * P<005 EL +.56*** ”04 ** p<.o1 *** m *** P<0001 PEI +031 “005 43144 EF «52% +.11 -. m _. -x-x- H-x- * m +001 +002 -029 -009 +029 IL IF EL PEI EF Table 7.3 Total Behavioral and Penile Measure Comparisons . Measure II. IF EL PEI EF PEPI PP IF 71 EL 67 77 PEI 64 76 79 EF 34 49 38 40 PEPI 64 86 74 '81 44 PP 18 23 22 27 14 33 PH 16 20 22 22 11 23 20 292 Table 7.4 The Number of Same and Opposite Direction of Effect (Same/Opposite) for Measure to Measure Comparisons of All Variables. Measure IL IF EL PEI EF PEPI PP IF 6/20” x2 Statistic EL 32/5*** 17/18 * P<.05 Hat- ~x~x~ H P < '01 PEI 26/8 11/17 27/11 *H P (.005 EF 3/18*** 17/9 2/22*** 3/18*** PEPI 6/33” 37/6*** 1007*“ 803*“ 223/1*“ PP o/7*** 11/1*** 2/7 1/9* 9/o*** 12/1*** PW 1/7* 9/2* 2/10* o/9*** 6/1 12/o*** 9/o*** IL IF EL PEI EF PEPI PP Table 7.5 The Ratio of the Major Same or Opposite Measure Correspondence to the Total Possible Number of Comparisons. Measure IL IF EL PEI EF PEPI PP PW IF .282 EL .478 .234 EF .526 . 347 . 579 .450 PEPI .516 .430 .500 .407 .636 PP - 389 .478 - 318 . 333 . 643 - 364 PW .438 .450 .455 .409 .545 .522 .450 Beh. AV .442 .303 .42? .366 .508 .498 All AV .434 .349 .415 .367 .533 .482 .425 .467 293 Table 7.6 Sensitivity Indicators The Ratio of the Number of Significant Effects to Total Treatment Conditions. Variable Class Change/Total counts IL IF EL PEI EF PE PI Intrinsic 7/10 1/10 6/11 6/11 5/10 7/10 5/8 Beh. & Stim. 12/23 21/35 12/23 11/23 10/17 22/26 7/16 Sensory 8/10 5/11 7/8 4/7 5/7 11/13 11/14 Gonadal Horm. 6/10 7/15 9/15 11/17 6/7 23/27 22/26 Androgens 7/12 5/9 7/11 13/19 1/5 17/28 14/19 Drugs 3/12 4/16 4/14 4/16 2/3 10/24 8/19 Non-Hormonal 27/43 27/56 25/42, 21/41 20/34 40/49 24/38 Hormonal 13/22 12/24 16/26 24/36 7/12 40/55 36/45 All 42/77 43/96 45/82 49/93 29/49 90/128 67/102 Sensitivity Ratios NoneHormonal .628 .482 .595 .512 .588 .816 .605 Hormones only .591 .500 .615 .667 .583 .727 .800 Drugs .167 .250 .286 .250 .667 .417 .421 All (no drugs) .615 .488 .603 .584 .587 .769 .711 All .545 .448 .549 .527 .592 .703 . 657 294 the IF had an equal distribution in direction of effects paired with the other measures). The poor directionality of IF effects, no doubt, caused the lack of correlation with other measures. Sachs and Barfield (172) also considered the IF highly stable. The remaining measures, excluding the PE, showed good correlation among one another (Table 7.2), indicating a reasonable degree of unity. The propensity for their effects to be in the same direction among the IL, EL, and PEI, and the opposite direction for EF compari- sons was significant in all cases (Table 7.4). Although the IL, EL, and PEI were similarly affected, little distinguished one from another. The PEI was somewhat less sensitive to change than the EL and IL, and the IL was the more labile, to minor degrees. The three were consistent across the different variable classes (Table 7.6). The correlations (Table 7.2) among the three measures were all significant, but not large enough (better than t 0.80) to assume redundancy and eliminate any one from contention. Similarly, the EF correlated with the three latency measures to about the same degree, but inversely. The BF could not be reasonably eliminated either. Unexpectedly, the PE, representing all the responding male ratios because of its greater lability, proved the most responsive measure of all behavioral measures. It was the most likely to change in response to experimental treatments, which was demonstrated by its higher sensitivity ratios (Table 7.6). The PE had significant directional pairings with all other measures (Table 7.4), but when the magnitudes of effect were correlated, the PE correlated poorly with all measures (Table 7.2), indicating substantial independence. The PE was more sensitive than the EF, but as the correlation was 29S poor, the PE evidently did not reflect the same mechanism(s) of action; the PE might have represented satiety effects, in part, but certainly not in total. The PE seemed more an indication of behav- ioral degeneration as a whole rather than inhibition or stimulation of particular behavior control mechanisms. The general degeneration was most noticeable under conditions that halted copulation by the first ejaculation - where satiety effects could not be observed, as when penile neural output was eliminated. The degrees of redundancy were based on the correspondence (Table 7.4) of the parallel direction of effects or their opposition in two measured comparisons. The BF and the PE or PI were the most alike, demonstrated by the correspondence ratio of 0.636 (Table 7.5). In addition, the EF followed by the PE-PI showed the higher corres- pondences with all the other measures, as indicated by the average correspondence ratios of 0.508 and 0.498, respectively. This gave a further indication of an involvement of satiety with all the other behavioral mechanisms. As expected, the imperturbable IF had the least correspondence with the other behavioral measures. In the beginning, the elimination of one or more behavioral measure(s) was anticipated. However, the level of correspondence was not sufficiently high to warrant the elimination of any one measure from a composite male measure. Even when the parallel lack of effect (no change in two measures) correspondence was added to the directional correspondence, the average correspondence ratio for the EF and PE-PI were 0.662 and 0.652, respectively; not a substantial improvement. Therefore, the only measure that might be discounted in the activity of a composite sexual behavior measure was the IF. The lack 296 of change to a variety of treatments helped little in the elucidation of underlying operations. The fact of the IF stability was, however, noteworthy. As the correlations between measures were too similar to distin- guish their relative importance and a reliable mathematical composite would require clear definition of relationships, only the very general relationship could be put forward. The general form of a composite would probably follow: (IL)(EL)(PEI) W + (PE-PI-PM) The latency measures were interrelated by the correlations, and the inverse correlation with the EF was also indicated. No indication of differential relations was found among the different variable classes. The weighting of the four factors would require further study. The PE and its cognates were related differently to the other measures because the correlated effect was poor, and its reflection of a more general behavioral effect was indicated. Furthermore, the PE's demonstrated sensitivity would require a heavy weighting. Although the given results did not conclusively define a male sexual behavior composite, the demonstrated interrelation of the behavioral measures indicated that a composite male measure could be developed. APPENDICES APPENDIX A APPENDIX A The Input Variables The input variables have been categorized into eight divisions, established by variable type and program organization. The intrinsic variables refer to the variables determining the normal intact male rat. The test variable category defines the test situation. The experimental variables deal with a variety of manipulations of the males' behavior, sexual object and environmental stimuli. The next division is the sensory variables. The remaining divisions deal with various hormonal manipulations, including a division for the major gonadal hormones (castration, testosterone, and estrogens), the minor androgens, nongonadal hormone treatments (primarily pituitary hormones and endocrine gland removals), and the grouping of anti-androgen, anti-estrogen, and aromatase inhibitor drugs with an additional few miscellaneous variables. Each division includes both real continuous variables and integer controller variables; fixed point designations should be assumed unless integer values are a stated requirement. I. Input Variable Descriptions A. Intrinsic Variables .ST - The male rat strain: 1- theborg (G) 5- Mixed strains (M) (integer) 2- Long-Evans (LE) 6- Holtzman (H) 3- Sprague-Dawley (SD) 7= Israeli 297 298 SR - The number of the ejaculatory series (not a designated variable). NSR - The maximum number of calculated ejaculatory series (preset at 5.0). A - The age (days) of the males from birth (200 days is preset). YMON - The month of the year of testing. The months are designated from 0.0 to 12.0, referring to the beginning of January to the end of December (1 day 3 0.033). B. Test Condition Variables TNO - The number of the test in a series of repeated tests. TDN The hour of the start of the sexual test during a 24 hour day. A light cycle of 12L:12D is assumed (the dark period is 0.0 to 12.0 hours and the light period is 12.0 to 24.0 (0.0) hours.). LTPER - The alternative light cycles ranging from constant dark (0.0) to constant light (24.0) (preset at 12.0(12L:12D)). TBT - The number of days separating repeated tests. TMIN - The test length in minutes measured from the introduction of the female to her removal. (Sexual satiety is assumed greater than 120 minutes.) COPMIN - An exact time during the test: the number of minutes into the test from the introduction of the female to the test arena (cannot be longer than TMIN). SEXEXT - The number of tests of sexual behavior given previous to the current experimental test. The sexual experience in- cludes naive males (0.0 tests) to experienced males (4.0 or more tests). NRACOND- The condition of caging during early development, usually from weaning to 90-100 days of age. The integer values include: 1 - isolation - housed alone 2 - cohabitation - with both males and females 3 - segregation - with a group of males TDRAIS - The age in days at the initiation of the NRACOND caging con- dition. Weaning provides a convenient marker at approxi- mately 30 days of age. However, the treatment can begin as early as 2 days of age. 299 C. Experimental Manipulation Variables SCREEN EICI NEICI NPI EPEI NFRESH ISHOCK ISS ECSDY The controller of a special caging condition where the male or female rat(s) are separated from the experimental male by a double wire mesh screen, that prevents physical contact. This is an alteration of the NRACOND conditions. Any integer greater than 0 activates it. The length (min.) of the enforced interval between intro- missions. ‘ The controller for the type of experimental use of the EICI. The female (0 or 1) or the male (5) can be removed from the arena. The EICI can be instituted after each intromission (10) in a series or only after a single designated intromission during each series (1 or 5) or after all Is out to and including satiety (50). The number of intromissions before any manipulation is made (used in conjunction with NEICI - l or 5). The length (min.) of the enforced interval initiated fol- lowing ejaculation. The male is denied access to the female for the designated period. The controller for a change of the stimulus female. The replacement female could have no immediate prior copula- tory experience (Fresh) or have had experience (Used) with another male. The female may be changed at each ejaculation (l), at satiety (10), at satiety but handled at each ejaculation (20), or at both each E and satiety (25). The integer controller for stimulation by electrical shock. The shock was applied to the flank, tail, or back by an attached wire or through the feet via an electric grid floor. The intensity and duration of the shock varied, usually shock was set at just below the squeal level for each rat (10). Otherwise, the shock was set at a signi- ficantly higher level (5). The integer controller for the intensity of the delivered shock. The intensity is altered by adjustment of the number of shocks (20 = 10-20 shocks/min.) or the dura- tion of shock (I - 5 min. shock). The norm is 1-2 shocks/min. set in bursts. In addition, the criterion of shock to seminal emission (50) can be used. The number of days of treatment with electro—convulsive shock (ECS), one shock per day via the ears. 300 COND - The controller referencing a number of classical conditioning paradigms. The unconditioned stimulus (UCS) is access to a sexually receptive female and the ensuing sexual behav- ior is the unconditioned response (UCR). The conditioned stimulus (CS) and the conditioned response (CR) vary. Both positive and negative reinforcement is used. 1 - a light is the CS. 5 I a loud bell is the avoidance CS. 10 - a pedal push (CR) is required for the female. 15 - a bar press (CR) is required for the female. 20 - an avoidance shock (CS) is given in the presence of the female; the male is tested later without shock in the same conditioning cage. 25 - the same as 20, but the male is tested later in a novel cage. 30 - no shock is given but tested in a novel cage - a conditioning control showing novel cage effects. COPLIM - The controller for manipulation of copulatory performance. 1 - group testing - more than one male-female pair in one arena. 2 8 testing pairs in adjacent arenas, one pair per arena. 3 - testing in a novel arena. 4 - testing in an arena one-half the size used previously. 5 - testing to exhaustion at least once a week. 6 - testing to 2 Es once a week prior to the test. 7 - testing to less than 4 Is/week prior to the experi- mental test. COLLAR - The integer controller for the use of a large neck collar that prevents genital grooming, activated by a value greater than 0. SEXSTIM - The controller for the copulatory stimulus allowed the male. The male can be exposed to a particular stimulus for a number of prior tests and then tested with a receptive female, or the particular stimulus may be presented to the male only on the experimental test. A few miscel- laneous treatments are included also. 1 - a receptive female sexual stimulus (normal). 2 a early exposure to a receptive female. 5 - a receptive female stimulus of a different strain. 10 - another male as stimulus. ll - previous experience with a male stimulus. 30 - handling during the test. 40 - observation by experimental male of a copulating pair immediately prior to testing. 60 - the stimulus of a female with a closed vagina. 75 - a nonreceptive female stimulus. 80 - a small male test stimulus. 85 87 90 92 95 301 a small guinea pig test stimulus. - an immobile (anesthetized) receptive female or a small rabbit stimulus. - prior exposure to a receptive female, but prevented from physical contact (no contact female). - exposure to female odors. - left alone in a test arena prior to testing for long durations (40-60 minutes). D. Sensory Variables. NSEN(K) - The controller integer list for all sensory variables. Each .Oyesl of the 13 values for this controller designate a ' for that variable. A list of up to 12 values can be set for this array; any or all of the variables below may be called in any order or combination. The following variables deal with the removal of a sensory organ or the alteration of the perception of sensory stimuli. 13 Olfactory bulbectomy (OBX): The removal of the olfactory bulbs, peduncle, or neural tissue adjacent and caudal to the bulbs. Anosmia: The removal of smell without damage to the brain. The nasal epithelium is scraped and a caustic fluid is introduced into the nasal passages with or without cutting the olfactory nerve. Blinding: The removal of sight by enucleation. Clansectomy: The removal of the sensitivity of the penis by surgically removing the glans penis. Penile bonectomy: The removal of some penile rigid- ity by surgical excision of the penile bone, usually prior to puberty. Penile nervectomy (PNX): The elimination of sensory and/or motor innervation to the penis and pubic area by sectioning the Pudendal, Pelvic, or the Dorsal Penile Nerve. (The CUT variable serves the same function with integer value > 0). Penile anesthesia: The nonsurgical removal of penile stimuli. A topical anesthetic (e.g. Lidocaine) is liberally swabbed on the penis prior to testing. Precopulatory experience: The experimental male is exposed to a copulating pair of rats but prevented from participating by containment in a clear vented box. Self-stimulation (SS): The male is implanted with an electrode in the ventrolateral thalamus ("plea- sure center“) and conditioned to bar press for stimulation. The stimulation continues to seminal emission before testing with a female. 302 10 I Noise: The cOpulating pair is exposed to a loud white noise during the test period. 11 - Multiple organ removal: Two or more sensory organs are removed or prevented from functioning; it in- cludes any combination of OBX, anosmia, blinding, PNX, or cutting the facial (5th) nerve. 12 - Facial (5th) nerve cut: The cutting or sectioning of the nerve innervating the vibrissae and the skin of the snout. 13 - None: This value bypasses all of the above. E. Major Gonadotropic Hormone Variables In all cases where a dosage and duration of treatment variable exists for a particular hormone, both must have a designated value to operate effectively in the model. CAST - The number of days after the removal of the testes. CASTH - The number of minutes after castration. CASTD - The males' age in days at the time of castration. CRYPTD The number of days after the testes were placed into the abdominal cavity (cryptorchidectomy). DPC - The number of days between castration and the initiation of the injection of any hormone or drug. A value less than 5.0 represents a maintenance regime and a value of greater than 10.0 represents a recovery regime. INJl The integer controller for limits placed on the number of injections given or for a non-injection hormone delivery. 0 - A normal series of injections given at least once a day over a period of days. 1 - Only one injection is given, usually as a large dosage, and testing proceeds from that day onward. 5 a A small number of injections are given (2-10); the injections are spaced more than one day apart. 15 - Hormones are introduced by infusion, usually into the jugular vein. 20 - A silastic capsule containing the hormone is implanted under the skin (used for any hormone except testosterone, that has a separate variable). DTT - The dosage (ug) of free testosterone given per day. DTTP - The dosage (ug/day) of testosterone propionate. DYTT - The number of days of treatment with free testosterone. DYTTP - The number of days of treatment with TP. 303 TIMP - The dosage of testosterone given as the length in milli- meters of a silastic capsule implant. (DYTT must be set along with this variable for treatment days.) TA - The number of days of treatment with testosterone acetate NTA - The integer controller for the injection of 10 mg of TA in a single injection (value > 0 sets it). NTC - The integer controller for the injection of 10 mg of tes- tosterone cyprionate in a single injection (value > 0 to set). NTE - The integer controller for the injection of 10 mg of tes- tosterone ethanate in a single injection (value > 0 to set). DEB - The dosage (ug/day) of estradiol benzoate (EB). DEl - The dosage (ug/day) of estrone (E1). 0E2 - The dosage (ug/day) of free estradiol (E2). DE3 - The dosage (ug/day) of estriol (E3). EBDY - The number of days of treatment with EB. ElDY - The number of days of treatment with E1. EZDY - The number of days of treatment with E2. E3DY - The number of days of treatment with E3. E2DPDI - The number of days of treatment with estradiol dipropion— ate (use DEB for dosage). F. Androgen Variables If both duration and dosage variables exist for a particular androgen, both variables need to be designated. DDHT - The dosage (ug/day) of free dihydrotestosterone (DHT). DDHTP - The dosage (ug/day) of dihydrotestosterone propionate (DHTP). DHTPDI - The number of days of treatment with either DHT form. DAND - The dosage (ug/day) of androsterone in oil. ANDDI - The number of days of treatment with androsterone. DWAND - The dosage (ug/day ) of androsterone in water. DANDOL - The dosage (ug/day) of androsterone-dial in oil. ANDOLDI - The number of days of treatment with androsterone-dial. DTANDOL - The dosage (ug/day) of TD-androsterone-diol. DHEPAND HEPANDI DDHEA DAEOL DSAEOL AEOLDI DHOAEN HOAENDI DAAAOL AAAOLDI DBAAOL BAAOLDI DAAONE AAONEDI HTPDI 304 The dosage (ug/day) of dehepiandrosterone. The number of days of treatment with dehepiandrosterone. The dosage (ug/day) of dihydroepiandrosterone or epi- androsterone. The dosage (ug/day) of 4-androstenediol. The dosage (ug/day) of S-androstenediol. The number of days of treatment with either androstene- dial. The dosage (ug/day) of lip-hydroxy-androstenedione. The number of days of treatment with llfl-hydroxy-andro- stenedione. The dosage (ug/day) of 3a-androstanediol. The number of days of treatment with 3a-androstanediol. The dosage (ug/day) of 3p-androstanediol. The number of days of treatment with 3fl-androstanediol. The dosage (ug/day) of androstanedione. The number of days of treatment with androstanedione. The number of days of treatment with l9-hydroxytestos- terone propionate. G. Pituitary and Nongonadal Hormone Variables, etc. HPI PLT PLLH PLFSH DLH DIULH LHMIN DFSH FSHMIN DPRL The number of hours after a hormone injection. The systemic blood plasma level (ng/ml) for testosterone (T). The systemic blood plasma level (ng/ml) for LH. The systemic blood plasma level (ng/ml) for FSH. The dosage (ug/lOO 3 BW) of LH injected per day. The dosage (IU/day) of LH injected. The number of minutes after injection with LH. The dosage (ug/lOO g BW) of FSH injected per day. The number of minutes after injection with FSH. The dosage (ug/day) of injected prolactin. The dosage (IU/day) of Human Chorionic Gonadotropin (HCG). The number of minutes after the injection of HCG. 305 (mg/day) of progesterone. (mg/day) of dihydro- or hydroxy-progesterone. (mg/day) of pregnenolone or pregnandione. (mg/day) of dehydropregnenolone. of days after hypophysectomy (removal of the pituitary gland). of hours after adrenalectomy (removal of the glands). of hours after thyroidectomy (removal of the gland) o of days after pinealectomy (removal of the pineal gland). DPROG - The dosage DHPROG - The dosage DPREG '- The dosage DHPREG - The dosage H -_ The number HAX - The number adrenal THX - The number thyroid PINX - The number STARV - The number minimum of days of starvation (food deprivation). The length of treatment for behavioral effect is six days. H. Drug Variables DFM DYFM DCYA DFL DYFL DSH With the exception of FM, the drugs listed below are usually used in conjunction with testosterone in castrate males, and in a few cases with estrogen. To obtain a demonstration of anti-androgenic or anti-estrogenic effects over days of treat- ment, both drug and hormone variables must be designated. - The dosage - The number - The dosage - The dosage - The number - The dosage l. Androgen mimetic drug (mg/day) of fluoxymesterone (FM) injected. of days of treatment with fluoxymesterone. 2. Anti-androgen drugs (mg/day) of cyproterone acetate. (mg/day) of flutamide. of days of treatment with flutamide. (mg/day) of Shering-7l4. 306 3. Anti-estrogen drugs DMER - The dosage (mg/day) of MERrZS. DCI - The dosage (mg/day) of 01-628. DCLOM - The dosage (mg/day) of Sigfclomiphene. DICI - The dosage (ug/day) of ICI-46474. 4. Aromatase inhibitors (block the conversion of testosterone to estrogen) DMET - The dosage (mg/day) of metopirone. METOPDI - The number of days of treatment with metopirone. DACT - The dosage (mg/day) of aminoglutethimide (AGT). AGTDI - The number of days of treatment with aminoglutethimide. 307 II. Preset Input Variable Values All input variables and their increment variables are preset prior to any designation of values by the user. The total of all the preset values produce an output consistent with the response of a normal group of control males given no experimental or hormonal treatments. There- fore, the user need only designate those variables in which he has an interest. Increment variables do not exist for the integer controller variables. The input variable and its increment variable (contained within the BINC array) are listed below with the preset values estab- lished within the pregram. input increment variable value variable value A. Intrinsic Variables ST 1 none SR 1.0 none (internal operation) NSR 5.0 BINC(2 0.0 A 200.0 BINCEl 7.0 YMON 6.0 BINC 4 0.23 B. Test Variables TNO 2.0 BINC(8) 1.0 TDN 5.0 BINCE3 0.0 LTPER 12.0 BINC 5 0.0 TBT 7.0 BINC(7 0.0 TMIN 99.0 BINC(9 0.0 COPMIN 60.0 BINC(15) 0.0 SEXEXT 10.0 BINC(6) 1.0 NRACOND 3 none TDRAIS 35.0 BINC(10) 0.0 C . Experimental Manipulation Variables SCREEN 0 none EICI 0.0 BINC(11) 0.0 NEICI 0 none NPI 0.0 BINCE13; 0.0 EPEI 0.0 BINC 12 0.0 NFRESH 0 none 308 input increment variable value variable value ISHOCK 0 none 18$ 0 none ECSDY 0.0 BINC(14) 0.0 COND 0 none COPLIM 0 none COLLAR 0 none SEXSTIM 0 none Sensory Variables (controller list) NSEN(K) 13*13 (13 consecutive 13s) Major Gonadotropic Hormone Variables CAST 0.0 BINC(16§ 0.0 CASTH 0.0 BINC(17 0.0 CASTD 30.0 BINC(19; 0.0 CRYPTD 0.0 BINC(20 0.0 DPC 0.0 BINC(18) 0.0 INJl 0 none DTT 0.0 BINC 22 0.0 DTTP 0.0 BINC§21 0.0 DYTT 0.0 BINC 24 0.0 DYTTP 0.0 BINC§23 0.0 TIMP 0.0 BINC 25 0.0 TA 0.0 BINC 26 0.0 NTA 0 none NTC 0 none NTE 0 none DEB 0.0 BINC(27 0.0 DE1 0.0 BINC(28 0.0 DE2 0.0 BINC(29 0.0 DE3 0.0 BINC(3O 0.0 EBDY 0.0 BINC 31 0.0 E1DY 0.0 BINC 32 0.0 EZDY 0.0 BINC 33 0.0 E3DY 0.0 BINC 34 0.0 E2DPDI 0.0 BINC(35 0.0 Androgen'Variables (all input and increment variables preset at 0.0) input increment input increment DDHT BINCE37 DAEOL BINCE47 DDHTP BINC 36 D5AEOL BINC 49 DHTPDI BINC(38 AEOLDI BINC(48 G. input DAND ANDDI DWAND DANDOL ANDOLDI DTANDOL DHEPAND HEPANDI DDHEA HTPDI and increment variables are preset at 0.0) HPI PLT PLLH PLFSH DLH DIULH LHMIN DFSH FSHMIN HCGD HCGM Drug Variagles (all of the input and increment at 0.0 DFM DYFM DCYA DFL DYFL DSH increment BINCE39 BINC 40 BINC(59 BINC€60 BINC 61 BINC(63 BINC€54 BINC 55 BINC(56 E BINC( 58) Pituitary and Nongonadal Hormone Variables, etc. (all of the input BINC(64 BINC(77 BINC(78 BINC(79 BINC(66 BINC§67 BINC 65 BINC§68 BINC 69 BINC(70 BINC(71 BINCE84 BINC 85 BINC(89 BINC(86 BINC(87 BINC(98 i ) 3 § 1 3 309 input DAEONE AEONEDI DHOAEN HOAENDI DAAAOL AAAOLDI DBAAOL BAAOLDI DAAONE AAONEDI DPRL DPROG DHPROG DPREG DHPREG H HAX THX PINX STARV DMER DCI DCLOM DICI DMET METOPDI DAGT AGTDI increment BINCE5O BINC 51 BINC ( 52 BINC(53 BINO(41 BINC(42 BINCE43 BINC 44 BINC(45) BINC (46) BINC(72) BINC(733 BINC(74 BINCE75; BINC 76 BINC(80 BINC(81 BINCEBZ BINC 83 BINC(99) variables are preset BINC 94 BINC 95; BINC(96 BINC§883 BINC(9O BINCE91 BINC 92 BINC(93 APPENDIX B APPENDIX B Standard Functions 1. Straight line : y = a-x + b 2. Curvilinear functions : a. Functions showing a decelerating increase with increasing values of "x". eygrx— a-x x + 1) y 2) y = O‘ ("a" controls the rate of increase and "b" establishes the maximum amplitude) b. Logarithmic functions (show a decelerating increase): 1) Natural logarithm. (base "e" . y = a-ln(x) 2) Common logarithm (base 10): y = a'l°8(X) c. The Inverse (showing a decelerating decrease with increasing " x") a y =‘; 3. Exponential Functions : a. Functions of "x" raised to an exponent. y a-xn (general form) - 2 x3 y - a-x or y = a' (usual specific forms) b. Functions of "e" s 1) y = A.ea-x (accelerating increase) 2) y 3) II as 6 w E? (decelerating decrease) — A-e- (decelerating decrease) ‘4 l 310 311 Standard Functions (cont.) 4) y = A(1 - e-a(x-z)) (decelerating increase) ("A" is the amplitude - in the case of the negative exponent the curve ranges between 1.0 and 0.0 with A=l.0. "a" is the rate function controlling the rate of acceleration or deceleration. "z" shifts the entire curve to the right or left along the "x" axis. ) 4. Functions with contained exponents: a. Sigmoid functions ("8" shaped curves) : 1) y=Aolo+(A-A)ma] 2) y=A°+(A1'A°)['1+1“‘ ( The curve ranges from the minimum value, A0, to the maximum value, A passing through the midpoint value of "y" at 10 the "c" value. The curve ranges from low to high (1) or from high to low (2). Again "a" controls the rate of change.) b. Other functions : a 1) y = (X/C) (shows accelerating increase, if a:-l, and decelerating increase, if a‘l.0, (- = a ratio of r.05) but the model provided an effect. d - E/C ratios refer to (cast. + hormone)/ cast., unless intact males were utilized. The symbol M_refers to a maintenance regime and the symbol R_refers to a recovery regime. . e - The response was equivalent to that of intact males at the reported dosages. SEXUAL BEHAVIOR AND PENILE BIBLIOGRAPHY 10. 11. 12. Sexual Behavior and Penile Bibliography Adler, N. and Bermant, G. (1966) Sexual Behavior of Male Rats: Effects of Reduced Sensory Feedback. J.C.P.P. 61: 240-243. Allen, J. A. and Boice, R. (1971) Effects of Rearing on Homosex- ual Behavior in the Male Laboratory Rat. Psychon. Sci. 23: 321-322. Anderson, E. E. (1936) Consistency of Tests of Copulatory Frequency in the Male Albino Rat. J.C.P. 21: 447-459. Arvidsson, T. and Larsson, K. (1967) Seminal Discharge and Mating Behavior in the Male Rat. Physiol. Behav. 2: 341-343. Ball, J. (1937) Sex Activity of Castrated Male Rats Increased by Barfield, R. J. and Geyer, L. A. (1975) The Ultrasonic Postejac- ulatory Vocalization and the Postejaculatory Refactory Period Of the Male Rate J.C.P.P. 88: 723-7340 Barfield, R. J. and Krieger, M. S. (1977) Ejaculatory Behavior of Male and Female Rats: Effects of Sex Hormones and Electric Shock. Physiol. Behav. 19: 203-208. Barfield, R. J. and Sachs, B. D. 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