LIBRARY Michigan Sula University ' This is to certify that the thesis entitled MATHEMATICAL MODELLING OF ISOTOPE EXTRACTION FROM SKELETAL MUSCLE VASCULATURE presented by Mark Alan Holmes has been accepted towards fulfillment of the requirements for M.S. , Chemical Engineering degree in Major professor November 10, 1978 Date 0-7639 MATHEMATICAL MODELLING OF ISOTOPE EXTRACTION FROM SKELETAL MUSCLE VASCULATURE BY Mark Alan Holmes A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Chemical Engineering 1978 ABSTRACT MATHEMATICAL MODELLING OF ISOTOPE EXTRACTION FROM SKELETAL MUSCLE VASCULATURE BY Mark Alan Holmes The selection of parameter estimates and bounds in a mathematical modelling technique was examined. A technique was developed to analyze washout curves from extraction studies on the canine gracilius muscle. The mathematical models emnployed simulated vascular beds with and without shunt channels. With the proper selec— tion of initial parameter estimates and bounds, the simulation technique adequately represented the experi- mental data. The two-path model (with shunt) describes the experimental data more accurately than the single path model (no shunt). However, from the analysis of the data available to date, it is not clear if the skeletal muscle vasculature contains shunt vessels. TO THE LORD, who got it done, and TO KAREN, who helped. ii ACKNOWLEDGEMENTS The author would like to express his appreciation to his academic advisor, Dr. Donald K. Anderson, for his guidance and assistance. He would also like to express his gratitude to Dr. Jerry B. Scott, Michael L. Goodnight, and Gregory A. Goslow for their advice and cooperation during the course of this research. Finally, he would like to thank his wife, Karen, for all of her support and assistance. The financial support of the National Institute of Health and the Michigan Heart Association is gratefully acknowledged. iii TABLE OF CONTENTS LIST OF TABLES . . . . . . . . . . LIST OF FIGURES O O O O O O C O O O NOWNCLATURE O O O O O O O O O O 0 INTRODUCTION . . . . . . . . . . . BAC KG ROUN D O O C O O O O O I O O The Capillary Bed . . . . . . . Work of Other Investigators . . . . Skeletal Muscle Studies . . . . Population Balance Studies . . . MODELS, EQUATIONS, AND COMPUTER PROGRAMS . Age-Distribution Functions . . . . Internal-Age-Distribution Function Exit—Age-Distribution Function . . Intensity Function . . . . . . The Models and Equations . . . . . Renkin Models . . . . . . . Friedman Models . . . . . . . Computer Program Modifications . . . METHODS AND RESULTS 0 O O O O O O 0 Surgical Procedure . . . . . . . Experimental Procedure . . . . . Results . . . . . . . . . . METHODS OF ANALYS I S O O O O O O O 0 Preliminary Calculations . . . . . Calculation of Tracer Recovery . . Mean Residence Time Calcuation . . Data and Weighting Factors . . . iv Page vi vii ix Parameter Estimations Plug Flow Volume Calculations Tank Number Parameters Fractional Flow Parameter . Ratio of Tank Volumes Diffusible Model Parameters The Modelled Data DISCUSSION . Experimental Procedure . Equipment Modifications Tracers Plug Flow Tubing Assumption Modelling Techniques Curve Fitting Capabilites . . Other Age-Distribution Conclusions Theory Comparison Suggestions APPENDIX . BIBLIOGRAPHY Functions 50 50 50 SO 51 54 54 55 55 55 56 57 68 LIST OF TABLES Table Page 1 Experimental Parameters . . . . . . . . 25 2 Data Set 10 - C - D . . . . . . . . . 26 3 Data Set 10 - C - s . . . . . . . . . 27 4 Data Set 10 - St - D . . . . . . . . . 28 5 Data Set 11 - C - D . . . . . . . . . 29 6 Data Set 24 - C - D . . . . . . . . . 30 7 Computer Derived Parameter Values . . . . . 38 8 Calculated Physical Parameters . . . . . . 39 vi Figure l 2 10 11 12 13 LIST OF FIGURES Schematic diagram of vascular bed . . . . Schematic diagram of a capillary network with change in flow direction. Adapted from Borghi (6, p. 2) . . . . . . . . . Schematic diagram of the one-channel, non- diffusible tracer model (Renkin) . . . Schematic diagram of the one-channel, diffu- sible tracer model (Renkin) . . . . . Schematic diagram of the two-channel, non- diffusible tracer model (Friedman) . . . Schematic diagram of the two-channel, diffu- sible tracer model (Friedman) . . . . Schematic diagram of experimental proce- dure O O O O O O O O O O O O 0 Comparison of one- and two-channel models to data set 11 - C - D . . . . . . . . Comparison of computer derived curve and data set 10 - C - D . . . . . . . . Comparison of computer derived curves and data set 10 - C - S . . . . . . . . Comparison of computer derived curve and data set 10 - St - D o o o o o o 0 Comparison of computer derived curve and data set 11 - C - D . . . . . . . . Comparison of computer derived curve and data set 24 - C - D . . . . . . . . vii Page 13 15 17 19 22 35 4O 42 44 46 48 Figure Page 14 Comparison of normalized washout data from tubing and muscle (data set 24 - C - D) and tubing only . . . . . . . . . 52 15 Schematic diagram of the two-channel, non- diffusible tracer model with stirred tanks (ST) replacing the plug flow section . . . . . . . . . . . . 53 viii E(t) E(9) I(t) 1(6) NOMENCLATURE In one-path model, fraction of the total system volume in the main flow stream, dimensionless. In two-path model, the fraction of stream 1 volume in the main stream, dimensionless. In the one-path model, ratio of tracer exchange rate to the main stream flow, dimensionless. In two-path model, ratio of tracer exchange rate to stream 1 flow, dimensionless. Concentration, mc/ml. Computer parameter, equivalent to B Exit-age-distribution function as a function of time, sec'l. Exit-age-distribution function as a function of dimensionless time, dimensionless. In two-path model, fraction of total flow going to stream 1, dimensionless. Constant, see equation 35, dimensionless. Internal—a e-distribution function as a function time, sec" . Internal-age-distribution function as a function of dimensionless time, dimensionless. Constant, see equation 15, dimensionless. In two-path model, number of stirred tanks in stream 2. In one-path model, number of stirred tanks in series. In two-path model, number of stirred tanks in stream 1. Constant, see equation 16, dimensionless. Constant, see equation 15, dimensionless. ix t Time, minutes; seconds. E Mean residence time, minutes; seconds. v Blood flow rate, ml/min; m1/min/100 gm. V Volume, m1; ml/lOO gm. a In two-path model, the ratio of the mean resi- dence time in stream 2 to the mean residence time in stream 1, dimensionless. B Constant, see equation 21, dimensionless. y Computer parameter equivalent to "a". 6 Fraction of total volume in the plug flow section, dimensionless. n In the two-path model, the ratio of the volume of a tank in stream 2 to the volume of a tank in stream 1, dimensionless. 6 Dimensionless time. 6 Variable, see equation 12, dimensionless. A(t) Intensity function as a function of time, sec-1. A(e) Intensity function as a function of dimensionless time, dimensionless. ¢ Fraction of tracer recovered, dimensionless. Subscripts B Blood D Diffusible I Injected ND Nondiffusible T Total system tubing tubing 1 Function 1 or stream 1 2 Function 2 or stream 2 X INTRODUCTION The goal of this research was to continue a study on the vasculature of skeletal muscle. In particular, this work involved further development of computer modelling techniques, initially presented by M. R. Borghi (6), to be used in the analysis of radioisotope pulse injection data obtained from canine gracilis muscles. The equations used in the computer simulations were derived from modelling techniques used extensively in the engineering field. A discussion of the work of other investigators, in both the engineering and physio- logical areas, is presented in the Background section. A description of the models and equations used is also presented. The data which were analyzed were obtained from experimental procedures described in detail by M. L. Goodnight (12). In brief, the gracilis muscle of a mongrel dog was isolated in situ, leaving only one artery leading to the muscle and one vein draining it. Radiolabelled compounds were injected as a bolus into the artery feeding the muscle, and samples of venous blood were taken serially and analyzed. The experimental data from the washout studies were converted to age-distribution curves and analyzed. The primary analytical method consisted of fitting the experimental results with computer generated curves of mathematical models. Discussion of the results and conclusions of this research is contained in the final section. BACKGROUND The Capillary Bed Flow through a vascular bed can best be described using the schematic diagram in Figure 1. Blood enters through the artery (A) which branches into arterioles (a) which branch into capillaries (c). Exchange of nutrients and metabolic wastes between the blood tissue occurs at the capillary level. The capillaries drain into venules (v) which, in turn, empty into veins (V). Vessel diameters range from 600 - 1,000 microns for terminal arteries and veins, 20 - 30 microns for the arterioles and venules, and 8 - 12 microns for true capillaries. True capillaries can also be distinguished from the larger vessels by their walls, since they con- tain only endothelial cells, while the walls of the larger vessels also contain smooth muscle and collagen fibers. Actually, the capillary network is far more complex than is indicated in Figure 1. For example, flow in a given capillary can, and does, change direc— tions as indicated in Figure 2. A more detailed des- cription of the capillary and its function can be found in Mountcastle (20, pp. 984-991). .pwn H9309; mo Emummfip oaumEmsom I...“ wusmfim .AN .m .mv acumen Eoum pwummpd .cofluomnwp 30am ca mmcmno cues xno3um: wumHHflmmo m mo Emummflp Denmamnomii.m muomwm cofluomufio 30Hm coon + WOrk of Other Investigators The work done by other investigators can roughly be divided into two groups: 1) those studying skeletal blood flow and, 2) those developing the modelling techniques. Skeletal Muscle Studies Two important contributors to research on blood flow through skeletal muscle are J. J. Friedman (8-11) and E. M. Renkin (22-25). Both have conducted indicator dilution studies on skeletal muscles, and each has pro- posed a theory to explain his observations. Friedman supports the hypothesis that skeletal muscle blood flow is best described as a flow limited, two-path system, where one path (referred to as the nutritive path) supplies oxygen and nutrients to the tissue, and the second path (or nonnutritive path) shunts excess blood around or past the capillary bed, as in an arteriovenous anastomosis. No anatomical anastomoses have been identified in skeletal muscle. However, a physiological shunt, consisting of preferen- tial pathways, may exist (see 6, Figure 1). In this system, the preferential pathways would act to shunt excess blood flow by the capillary bed, while the true capillaries would supply the nutritive needs of the muscle. According to Renkin's theory, nutrient supply to the skeletal muscle is permeability limited, with the possibility of one or more paths. In this study, only the one-path model was considered. The use of this model is consistent with Renkin's definition, since the additional stream(s) serve(s) as a source of additional capillaries for increased blood flow (22, 23). A third investigator, C. H. Baker (1-4, 19), has also been working in the analysis of blood flow through skeletal muscle vascular beds. Utilizing the parallel path model, he has attempted to calculate the volumes associated with radio-labelled red blood cell, albumin, and rubidium flow paths. POpulation Balance Studies In the engineering field, the work of Danckwerts (7) in 1953 is considered the forerunner of present tracer washout modelling techniques. In the area of physiology, indicator dilution studies were used as early as 1928 by Hamilton (13, 14), with detailed derivations by Zierler (18, 26-29). It is interesting to note that Zierler went through an analysis of vascular beds very similar to the one Danckwerts did with reactor beds one year earlier. The work in the physiological area has been further developed by investigators such as Martin and Yudelivich (17), while Levenspiel (16), Bischoff (5), and others (see citations in 15) have developed the modelling techniques formalized by Danckwerts in the engineering field. The research described inthis thesis involves applying engineering models to the study of the skeletal muscle vasculature. MODELS, EQUATIONS, AND COMPUTER PROGRAMS Age-Distribution Functions The equations used in this study are from a group of functions called age-distribution functions, which have been described previously (7, 21). The equations, or functions, describe the residence time of fluid elements in a theoretical, idealized system, which can hopefully be related to the physical system being examined. In engineering applications, this would include reaction mixtures flowing through reactor beds. In this biological study the equations are used to describe the residence time of blood in the muscle capillary bed. Three of the age-distribution functions are described below. Internal-Age-Distribution Function The internal-age-distribution function, I(t), is the age distribution inside the system, and has the units: fraction of ages per unit time. The "age" of any element is defined as the time, t, the element has spent in the system. From this, the fraction of elements in the vessel with ages between t and t+dt is given by I(t)dt. The function is normalized, which leads to 10 /”I(t)dt = 1 <1) Exit-Age-Distribution Function The exit-age—distribution function, E(t), is defined as the residence time distribution of the stream leaving the system. It is the distribution, or fre- quency, of fluid elements of a given age in the exit stream. It has the same units as I(t), and the fraction of the exit stream with ages between t and t+dt is given by E(t)dt. This function is also normalized which leads to °f°°Edt = 1 (2) The exit-age-distribution function is related to the internal-age-distribution function by _ -- é__ E(t) — wt dt I(t) (3) Intensity Function The intensity function, A, is defined as the fraction of fluid in the system of age t that will leave at a time between t and t+dt. It is related to the other two functions by m E A(t) = (4) wind H £1 11 The functions can be expressed in dimensionless form, where e, the dimensionless time, is defined as (5) CD u «Inf and t, the mean resident time, is defined as E = °I°°tE(t)dt (6) The dimensionless age—distribution functions then become E(e) = EE(t) (7) 1(9) = EI(t) (8) me) = E (t) = §{%-} ‘9) More detailed derivations of the functions can be found in the texts by Levenspiel (16) or Himmelblau and Bischoff (15). The Models and Pguations Borghi (6, pp. 11-57) develOped four models to describe the age-distribution functions for diffusible and non-diffusible tracers expected from the theories proposed by Renkin and Friedman. The models used con- sist of arrangements of ideal stirred and/or ideal plug flow vessels. In an ideal stirred tank, the entire contents of the vessel are completely mixed and uniform. 12 An ideal plug flow reactor is one in which there is complete mixing perpendicular to the direction of flow, but no mixing or diffusion along the direction of flow. Renkin Models As mentioned earlier, the Renkin hypothesis concerning blood flow is represented by a single pathway. For the non-diffusible tracer, the model consists of a plug flow vessel, (PF) followed by a series of equal volumed stirred tanks (ST) as shown in Figure 3. The age-distribution function is given by O for 8 5 e E(e) = 1 N N-l (10) N 9 exp (-N O) for 6 3 e \ F(N)(l-e) where V e=V§-F- (11) T 0 - e o—l_€ (12) The model for the diffusible tracer is similar to the model for the nondiffusible tracer. The diffusion model consists of the same plug flow tank and series of stirred tanks with the addition of a diffusion tank (DT). . 33:85 .3605 .3033 panamammaccoc .Hmccmzonmco can mo Emummac oaumfimcom I|.m musmwm game cmuuhum . em xame sous msam u mm 13 8m Em mm 14 The diffusion tank is used to represent the diffusion of tracer in and out of the interstitial space, and consists of a stirred tank which receives flow from, and sends flow to, the last stirred tank in the series as indicated in Figure 4. The dimensionless age-distribution func- tion for the single-path diffusion model is give by K Q '- _ N-i-l E(e) = (1 exp (-Q O)N£l [31+aR1)Qé] -exp (aQRlO) l-e) ._ 1‘1 (N-i-l)! K Q _ N-i-l _ (2 ) exp (-Q O)N£1 [31+aR2)Qé] -exp (aQRZO) 1-e ._ 1'1 (N-i-l)! (13) > < for 6- e and O for 6- e, where - _ _ 4aB(1-a) R12. = 1 a+B li/ l —1—+—B-—2' (l4) 2a(l-a) ( -a ) 1 R1 + B/(l - a) K2 = 2 (15) (l + aRi’)N-1 (R2 - R1) Q = aN - a + l (16) a 15 IX A \ .Acchmmv Hmcofi nmomuu manflm:MMA© .Hmccmnoumco on» mo Emummflp oaumEmcom.iuv musmwm xcme cowmsMMHo 1 Bo xcma pmuuflum I am xcmu 30am msam 1 mm Em 1"l|'| BO \ Em 16 Friedman Models The Friedman model is represented by a two- channel flow path. The nondiffusible tracer path is represented by a plug flow vessel followed by two parallel streams of stirred tanks, designated as streams l and 2. Stream 1 has N tanks, each having a volume V1, and stream 2 has M tanks, each having volume V2. A schematic diagram of the model is presented in Figure 5. The dimensionless exit-age-distribution function for this model is given by (NB)N ON 1 E(O) = f exp (- N80) T (N) (l-E) (MB/d)M 9M 1 ms + (l-f) exp - —— O P(M) (l-E) a (17) for 6 2 e, and 0 for 6 s e, where VPF e = __ (18) VT 0 = 9:2 (19) H I m l7 Hmcoe Hooch» waoflmsmwflpcoc xcme pmnuflum I am xcma 30am msam I mm N Emouum Em II II H Ecmuum 8m II II .HmccmnOIozu Em Em .Acmfipmwumv may no Emummflp oeumEmnomII.m musmflm 18 fMVz _ (20) a ’ (1-f)Nv1 B = f+(1—f)a (21) For the diffusible tracer, a diffusion tank (DT) is added to stream 1, as indicated in Figure 6. r‘ N-i-l £11138 N-l QB(l+aR])€-> E(O) = T—[exp (-069) .21 N_1_1 , :l - eXP(aQR189):| 1: N-i-l f B N-l QB(1+ )e 'QKZ T—y|:exp (-QBG) .21 [(N_i:lR)2, :1— - eXP(aQR280):I l: (1- f) 91“ MB M MB (22) TI-e) (M-l)! [3'] exp '[?9] for 6 2 e and O for e E e, where fame! a-f) (aN-a+1)V1 ‘23 ’ and s, G, R%, Ki, 8, and Q are as defined earlier. Computer Program Modifications The computer programs used in this research were versions of Fortran IV programs written by Borghi (6, p. 100). Four major modifications were made in the pro- grams. First, subroutine Area was eliminated because the values of t calculated in the subroutine were 19 .ACMEUOHHEV Hmpoe Hmomuu maoflmSMMHC .HmccmnOIo3u on» mo EMHmMHc cememcomII.m munmflm same cohmsmmhn I as some pouuwum I am xama scam made I mm _ I m Emmuum- # Em II.|.II.I Em - I H Emmuum Em aEm II I.II —mm—— 20 unreasonable, often greater than 200 seconds. Secondly, the channel volume calculations were found to be incor- rect and were replaced. Thirdly, nonzero values of E(e) were given by the model subroutines for values of 9 5 e, which is incor- rect. Alterations were made to account for the lower values. Finally, the main program and model subroutines were modified so the subroutines could be called up by calling either Model (used by the curve fitting program) or by calling the individual subroutine name (Series, Renkin, or Friedman; used with other programs). This eliminated the need to alter the subroutines' names each time they were used with a different program. The modified programs are presented in the Appendix. The optimization portion of the program (sub- routine Opt) and the plotting subroutine (Plotter) were not altered, and are not presented. METHODS AND RESULTS Surgical Procedure Mongrel dogs weighing approximately 20 kg were anesthetized with sodium pentobarbitol (30 mg/kg). The gracilis muscle (M, see Figure'N‘was surgically approached from the medial aspect of the hind limb, and all vessels except the primary artery and vein (indicated by A and V, respectively) were ligated. An essentially nonpulsatile, perfusion pump (P in Figure 7) was used to pump blood from the contralateral femoral artery to the primary artery. Venous blood from the muscle flowed through a sampling valve (SV), which, when activated, flushed intermittent, serial blood samples of equal volume into collection vials (CV). During the washout studies, it was desirable that the blood not be returned to the dog in order to eliminate the possibility of tracer recirculation. Therefore, during the washout periods, the blood leaving the sampling value was discarded, and dextran-70 was infused into the contralateral femoral vein at approxi- mately the same rate as blood was lost. Between studies, the blood was returned to the dog via the contralateral femoral vein. 21 .muspmooum Hmucmefluwmxm mo EmHmMHp OHumEmcomII.> musmflm $62"... 0550 >0 2 3203:. won 2 9 Ea... >m 23 The muscle was tied at its origin and insertion to eliminate any collateral flow, and the obturator nerve (O) was cut and connected to an electronic stimu- lator (S). Systemic arterial, perfusion, and venous pressures were monitored using pressure transducers, and recorded on a strip chart. Timing signals from the sampling value controller were also recorded. Experimental Procedure Sucrose, labelled with C14, and H3 tagged dextran (MW 82,400) were used as the diffusible and nondiffusible tracers, respectively. One bolus of a mixture of the tracers in saline solution was injected into the primary artery during each of the three wash- out studies performed on each dog. As a control, the first study was done without stimulation. The second injection was made immediately after electrical stimu- lation of the muscle (6v, 6 cps, 1.6 msec, for 30 seconds). The third injection was made after five minutes of histamine infusion (10 mg/ml at 0.5 ml/min). The histamine infusion continued throughout the sampling period. The blood samples were bleached with percholoric acid and hydrogen peroxide, then counted in a liquid scintillation counter. The counts obtained from the scintillation counter were converted to tracer 24 concentrations and the concentrations were then con- verted to exit-age parameters utilizing the formula C v E(t) = B (24) CIVI where C is the tracer concentration in the blood, v is B the blood flow rate, CI is the tracer concentration injected, and V is the volume of tracer solution I injected. A more detailed explanation of the experi- mental procedure is presented by Goodnight (12). Results Much of the experimental data could not be fully analyzed due to low tracer recoveries. In many instances, dextran recovery at the completion of a washout study was less than 70%. This was especially true for the stimulation experiments. Further complications arose from the need to use dextran washout parameters in analyzing the corresponding sucrose data.‘ The poor quality of the dextran data, therefore, often led to the discarding of otherwise usable sucrose data. Five sets of experimental data were selected for analysis: Four dextran washout studies and one sucrose washout study. Four of the sets of data are from control experiments, and one is from a stimulation ex- periment. Values for the experimental parameters are given in Table 1, and the .data is presented in Tables 2-6. 25 peace mama umma oe«« Ammouosm u m .cmuuxop u av “comma I coflumanfiwum u em .Houucoo u UV unmaflummxm I Hones: moo« o.ooa mma.~ om.mw m.mH o I U I am m.mm oom.m mm.mh m.ma o I U I Ha v.mm omm.m om.vh m.m I um I OH m.mm om~.m om.vh m.m m I O I OH m.mm om~.m om.vh m.m o I U I OH m Amocoommv lasso Aeaaxaso ««>Ho>oomm Hmomue mswommm unmflmz 30Hm UmumEHumm onEmm odomsz poon «pom mama mumumEMHmm HmacmsflnmmmeI.H OHQMB Table 26 2.-—Data Set 10 - C - D Time E(t) Time E(t) (seconds) (seconds- ) (seconds) (seconds-1) 2.00 .00000 102.48 .00103 8.28 .00000 108.76 .00087 14.56 .00003 115.04 .00084 20.84 .00288 121.32 .00076 27.12 .03385 127.60 .00064 33.40 .03982 133.88 .00059 39.68 .02563 146.44 .00045 45.96 .01460 152.72 .00039 52.24 .00986 159.00 .00035 58.52 .00585 165.28 .00028 64.80 .00401 171.56 .00029 71.08 .00303 177.84 .00028 77.36 .00249 184.12 .00025 83.64 .00179 190.40 .00023 89.92 .00137 196.68 .00021 96.20 .00122 202.96 .00019 27 Table 3.--Data Set 10 - C - S Time E(t) _ Time E(t) _ (seconds) (seconds ) (seconds) (seconds ) 2.00 .00000 102.48 .00132 8.28 .00000 108.76 .00116 14.56 .00003 115.04 .00106 20.84 .00243 121.32 .00096 27.12 .02684 127.60 .00089 33.40 .03069 133.88 .00082 39.68 .01827 146.44 .00068 45.96 .01065 152.72 .00065 52.24 .00713 159.00 .00062 58.52 .00500 165.28 .00061 64.80 .00373 171.56 .00057 71.08 .00299 177.84 .00055 77.36 .00245 184.12 .00052 83.64 .00202 190.40 .00047 89.92 .00172 196.68 .00046 96.20 .00152 202.96 .00045 28 Table 4.--Data Set 10 — St - D Time E(t) _ Time E(t) _ (seconds) (seconds ) (seconds) (seconds ) 2.00 .00000 108.76 .00108 8.28 .00003 115.04 .00095 14.56 .00007 121.32 .00081 20.84 .00193 127.60 .00064 27.12 .02188 133.88 .00058 33.40 .04498 140.16 .00049 39.68 .02953 146.44 .00053 45.96 .01502 152.72 .00036 58.52 .00579 159.00 .00030 64.80 .00416 165.28 .00027 71.08 .00291 171.56 .00025 77.36 .00217 177.84 .00021 83.64 .00173 184.12 .00019 89.92 .00170 190.40 .00017 96.20 .00136 196.68 .00016 102.48 .00127 29 Table 5.--Data Set 11 - C - D Time E(t) _1 Time E(t) _1 (seconds) (seconds ) (seconds) (seconds ) 4.00 - .00000 172.00 .00027 9.60 .00000 177.60 .00023 15.20 .01684 183.20 .00023 20.80 .05498 188.80 .00019 26.40 .03658 194.40 .00020 32.00 .01348 200.00 .00024 37.60 .00871 205.60 .00018 43.20 .00531 211.20 .00019 48.80 .00294 214.20 .00019 54.40 .00259 219.80 .00020 60.00 .00201 225.40 .00015 65.60 .00149 231.00 .00015 71.20 .00113 236.60 .00017 76.80 .00099 242.20 .00014 82.40 .00092 247.80 .00013 88.00 .00088 253.40 .00011 93.60 .00083 259.00 .00012 99.20 .00063 264.60 .00013 104.80 .00055 270.20 .00012 110.40 .00049 275.80 .00012 116.00 .00039 281.40 .00012 121.60 .00037 287.00 .00018 127.20 .00042 292.60 .00010 132.80 .00028 298.20 .00010 138.40 .00031 303.80 .00009 144.00 .00025 309.40 .00009 149.60 .00024 315.00 .00009 155.20 .00022 320.60 .00009 160.80 .00024 326.20 .00010 166.40 .00019 331.80 .00014 30 Table 6.--Data Set 24 - C - D Time E(t) _ Time E(t) _ (seconds) (seconds ) (seconds) (seconds ) 2.68 .00000 45.13 .00440 4.75 .00000 47.25 .00411 6.88 .00000 49.38 .00373 9.00 .00211 51.50 .00303 11.13 .01451 53.63 .00273 13.25 .05200 55.75 .00309 15.38 .07486 57.88 .00298 17.50 .08238 60.00 .00232 19.63 .04792 62.13 .00220 21.75 .04520 64.25 .00195 23.88 .02928 66.38 .00176 26.00 .02354 68.50 .00211 28.13 .01774 70.63 .00179 30.25 .01726 72.75 .00164 32.38 .01218 74.88 .00176 34.50 .00913 77.00 .00152 36.63 .00865 79.13 .00154 38.75 .00719 81.25 .00151 40.88 .00655 83.38 .00146 43.00 .00529 METHODS OF ANALYSIS Preliminary Calculations Calculation of Tracer Recovery The tracer recovery, I), is obtained by integration of the exit-age-distribution function. In equation form, the fraction of tracer recovered to time t is given by t ¢(t) =°f (E(t)dt (25) Since all of the tracer should eventually be washed out to the tissue, I(w) =.r” E(t)dt = 1 (26) Estimation of the tracer recovered during an experiment was made using Euler's estimation of the integral. The dextran tracer concentration in the venous blood was sufficiently low by the end of most experiments to justify the conclusion that all of the tracer that could be washed out of the tissue had been extracted. Extrapolation of the curves usually accounted for less than an additional 5-10% of the tracer recovery. There- fore, dextran data sets with less than 90% recovery by the last data point were not analyzed. The dextran 31 32 data set from the control experiment of dog number 11 was included, however, to illustrate the problem encountered with low tracer recovery. Mean Residence Time Calculation The equation for the mean residence time, E, was presented in Section II. (p. 11). The integration of the exit-age-distribution data was done graphically, as numerical techniques often gave unreasonable values due to the methods used to estimate the tail portion of the curve. The mean residence times for the sucrose data are only approximations. The tail portion of that data set made a more exact determination of t impossible. However, the data are adequate for illustration of the analytical techniques. Data and Weighting Factors For curve fitting purposes, the data beyond 6 = 2 or 3 could not be considered reliable (15, p. 72), and were not used in the analysis. To compensate for the large number of data points in the tail portion of the washout curves, the peak data point was weighted 10 times heavier than the other points. Once the initial optimization was completed, any necessary alter- ations in the curve fit could be made by using a weighting scheme to emphasize the portion of the curve where the improvement was desired. 33 Parameter Estimations Plug Flow Volume Calculations In order to obtain an estimate of the plug flow volume, V blood flow in the tubing from the PF' injection site to the muscle, and from the muscle to the sampling valve, was assumed to be plug flow in nature. The tubing volume used in the experiments, as calculated from the tubing diamter and length, was 1.9 i .4 ml. The total system volume, V , is related to E and blood flow, v, by V = vt (27) From this, a, the fraction of the total volume in the plug flow section,is given by 8 = VPF : vtubing :: 1._9 (28) VT VT vt The value of 6 could not be defined precisely since the primary artery and vein might also show plug flow characteristics. However, the calculated value was used as the first estimate of e in the curve fitting Optimization. 34 Tank Number Parameters Borghi (6) found that the two-stream model gave a better curve fit than the one-stream model, since the one-stream model could not simultaneously fit both the peak and the tail portions of the data adequately. Similar results were found in this study, as shown in Figure 8. When the two-path model was used, the lower limit on the number of tanks in each stream was set at 3.0 to avoid anomalies in the mathematics, and the upper limit set at 50.0. Initial estimates for N and M were taken as 3.0 and 15.0, respectively. Fractional Flow Parameter The fraction of the total fluid flow in stream 1, f, was allowed to range from 0.0 to 1.0. The initial parameter estimate was defined as 0.4, as the optimized values were usually less than 0.5. Ratio of Tank Volumes The ratio of a tank volume from stream 2 to a tank volume from stream 1, n, was allowed to range from 0.0 to 10.0, with an initial estimate of 0.2. The final, optimized values for this parameter were less than 0.5. Diffusible Model Parameters For the two-path diffusible model, the values for e, f, N, M, and n were defined by the corresponding , sec E(t) 35 0.06 r 0.05? KEY 0 data ' --- single flow channel ( Renkin ) 0,04 - —1wof|ow channal ( Friedman ) 0.02 - 0.0l '- Jn °. 0 20 40 so 8 IOO I20 I40 I60I80 I,sec Figure 8. Comparison of one- and two-channel models to data set 11 - C - D. 36 nondiffusible optimization. The values for f, N, M, and n were the same in the diffusible case as in the non- diffusible case, and SD was defined by It should be noted that stream 1 was defined as the nutritive (diffusion) stream, and stream 2 was defined as the shunt (nondiffusion) stream when the two- channel, diffusible tracer model was used. Therefore, with this model, f was the fraction of the total blood flow going to the nutritive stream, and N was the number of tanks in the nutritive stream. Likewise, n was the ratio of the volume of a tank in the shunt stream to the volume of a tankiJIthe nutritive stream. The value of "a" (referred to as Y in the compu- ter programs), the fractionof the total stream 1 volume which was present in the main stream, was calculated using the equation Gt a = -ND - - + (G l)tND tD . where G _ 1 - ND 14.51). 37 B (referred to as D in the computer programs) was defined as the ratio of flow to and from the dif- fusion tank to the main stream flow. The value of B was allowed to range from 0.0 to 100.0, with an initial estimate of 0.01. Since this was the only parameter being optimized in this model, the initial estimate was not as critical as in the case of the nondiffusibile tracer model parameters. Curve fitting of the sucrose data was done in which each of the streams from the corresponding dextran optimization was defined as the nutritive stream. The best fits for each configuration were compared, and the optimum fit was selected. The Modelled Data The mean residence times, optimized parameter values, and the sum of the squared residuals for each of the sets of modelled data are presented in Table 7. The calculated values of a and B, from equations 20 and 21, respectively, for the nondiffusible tracer model are also included in Table 7 to facilitate the use of equation (d) from Himmelblau‘s text (15, p. 74). The calculated physical parameters are presented in Table 8. Comparisons of the computer derived curves and the experimental data are presented in Figures 9-13. 38 cowumcmamxa Ham H manna mama >5. mm. vma. mHH. o.NH o.m mm. ham. mm.- o I U I «N mm. as. moa. mma. v.5H o.m we. mHH. 0.5m o I U I oa mo. he. mmo. mna. o.mH o.m mm. omm. o.ov I um I OH Hmm. omn.a ma. om. o.m o.v on. Hum. o.om m I U I oa mm. em. mud. mmm. o.m o.m mm. omm. o.mm m I U I OH Ne. em. mmm. mom. o.¢ o.m «m. 5mm. o.m¢ o I U I ca Aoamv m a mamnpflmmm c a > z z u w u pmumsvm I no Sam mumumEmumm «pom mumo mmsam> Hmuwemnmm pm>wnmo HODSQEOUII.h OHQMB 39 o.m o.om u u .Hmeos umomuu manflmsOMHa m u u .macoe Hooch» manflm5mmwpcoz N manmohaamm “Hm. coflumcmamxm you a canoe mama m.m m.H m.m m.m ~.~ a I o I «N o.HH m.m m.oa m.¢ H.H a I o I Ha m.m m.m m.e H.e ~.~ I um I OH H.m o.m me. s.m e.~ o.v m I o I oa o.m H.~ m.¢ m.m H.v m I o I ca ~.m e.~ H.m m.m o.v a I o I oH am coaxcns\as so ooa\as em coaxas em ooa\efls\as em ooH\Hs am ooa\as 30am mEdHo> madao> 3on mesao> pooam mnmaaflmmu macaw UOOHm mumHaflmmo HmhuhumuwucH mssao> «aAEmaHum ucsnmv «aafimmuum coflmnmmwpv 30am m ammuum a ammuum made I now mama mnmuafimnmm Hmowmhnm pmumHsoamoII.m magma 40 Figure 9.--Comparison of computer derived curve and data set 10 - C - D. E (6) LS " |.O- OSr 0.0 1...! 41 42 Figure 10.--Comparison of computer derived curves and data set 10 - C - S. .03 P- O N T E ( 1 )(seconds") .Ol- .00 \- 43 KEY — nondiffusible model, I = 55 seconds --- diffusible model. 1 = soseconds 1 (seconds) 44 Figure 11.--Comparison of computer derived curve and data set 10 - St - D. 45 2.0 " L5- 0.5 " 46 Figure 12.--Comparison of computer derived curve and data set 11 - C - D. 47 L5" L0- Amvm 0.5 - 48 Figure l3.--Comparison of computer derived curve and data set 24 - C - D. 49 L5 l' |.0 - on m 0.5 - 000.0 DISCUSSION Experimental Procedure Equipment Modifications Equipment modifications improved the quality of the data obtained from the experiments. The use of a chromatographic sample injection valve (12) eliminated the dead space problems encountered by Borghi (6). The use of a new timing device decreased the sampling inter- val from 4-6 seconds to 1-3 seconds. This increased the number of data points on the peak portion of the washout curve, and decreased the possibility of missing the peak portion of the curve, which occasionally occur- red with the previous timer. Tracers The primary difficulty encountered in this study was the poor quality of the dextran washout data. Over 60% of the control and stimulation experiments had dextran recoveries less than 70%, and in almost 40% of the experiments, dextran recovery was less than 50%. In contrast, only 20% of the control and stimulation sucrose recoveries were less than 70%. The sampling period for each experiment exceeded 250 seconds, allowing adequate 50 51 time for the complete extraction of the nondiffusible tracer (the blood recirculation time in the normal canine is approximatley 30 seconds). As can be seen in Figure 12, the low tracer recovery in data sets 11 - C - D made adequate fitting of the data impossible. The computer derived curve is above the data at all points. This problem also occurred when attempts were made to model the data from experiment 10 - C - S (recovery 85.5%). The low level of detected dextran recovery is believed to be due to the loss of the tritium through an exchange reaction. The possibility of replacing the 125 dextran tracer with I labelled albumin is being examined in the continuation of the project. Plug Flow Tubing Assumption One washout study was conducted on blood flowing through tubing, without the muscle. The normalized data collected in that experiment is compared to the non- diffusible tracer data from dog number 24 in Figure 14. Additional washout studies on blood flow through the tubing should be conducted to test the assumption of plug flow in the tubing. If that assumption is incorrect, it would be necessary to replace the plug flow section of the model with a series of stirred tanks (Figure 15). 2.0 *- L5 255 LIJ I.0 0.5 52 fl KEY o data from tubing and muscle a data from tubing only |.0 2.0 3.0 Figure l4.--Comparison of normalized washout data from tubing and muscle (data set 24 — C - D) and tubing only. 53 .coHuowm 30am mafia as» mcflomammu Aamv mxcmu pmunwum nufl3 Hapos umomuu manwm:MMApcoc .HmccoSOIozu an» MC Emummep aflumaacomII.mH anamam fi~£.....fl E II..- a 1... 2.63.5 54 Modelling Techniques Curve Fitting Capabilities With the exceptions of data sets 10 - C - S and 11 - C - D, the modelling techniques adequately represented the data (see Figures 9, 11 and 13). The primary requirements for the optimization techniques were high tracer recovery and the selection of reason- able initial parameter estimates and bounds. With the use of randomly selected parameters, the curve fitting program often "optimized" to curves which did not reasonably represent the data. The problem was especially pronounced when the data peak was not preferentially weighted. The large number of data points in the tail overemphasized that portion of the curve. In addition, if multiple maxima were present in the optimization scheme, random initial parameter selection may have caused the program to optimize around the incorrect maximum. Because of the uncertainty of the mean residence time calculations for the sucrose data set, that set was optimized using several different values for E. The best fits for the nondiffusible and diffusible models were presented (see Figure 10). As mentioned earlier, the low tracer recovery for this data set hindered the optimization efforts. However, since only one parameter is optimized with the diffusible tracer 55 model, the optimization technique is expected to perform adequately with more reliable data. Other Age-Distribution Functions The possibility of replacing the exit-age- distribution function, E(t), in the optimization tech- nique with one of the other-age distribution functions was considered. The information obtained from the internal—age-distribution function, I(t), is similar to that obtained from E(t), and there was no significant advantage to using the former. The intensity function, A(t), is helpful for detecting bypassing or stagnation in a flow system. The appearance of two or more maxima in the A(t) curve indicates the presence of nonuniform flow. However, the intensity function is not as useful as the other two functions in quantifying the effect (15, p. 73). Conclusions Theory Comparison It is not possible to draw any definite con- clusions from the data available at this time concerning which of the two hypotheses (Renkin's or Friedman's) is correct. The need for a two-path system to represent the data supports Friedman's theory, as does the high sucrose exchange rate which is inconsistent with the permeability limited system described in Renkin's theory. 56 However, analysis of more reliable data than are pre- sently available will be required to resolve the question. With the proper selection of initial parameter estimates and bounds, the modelling techniques described above can be expected to perform adequately. Suggestions The utilization of the sampling valve and control timer, developed by other investigators working on the project, has significantly improved the quality of the data. Replacing the radiolabelled dextran tracer and testing the assumption of plug flow in the tubing are areas which should be addressed in the continuation of the skeletal muscle microcirculation research. APPENDIX COMPUTER PROGRAMS 57 \ O I a o o a d I v o A o H I D o O o o “A at o «v 0 wt 5 x» o (m d I U: I. (a UR «a 0 to ov a A: 0‘ CC so an en v a: a. Hfl DA O on 00 20 0: mo OH m we 0" not.) «Ax 31 how u Dd to. five >~o D-mn mm: D a OOdA Com J°\I Oav omr< bah. mvdlfi-O 3d tea. a”. > om 23A mead Hdch\AO~ womaamhv ZZVNOOUU ~m>\mcv0h oo—mxzm tH~\\ >> 32hz ~h0~< mum (hw>thu::hhu~u WM J¢m< 0m I x Ihhu burntawmduom m WFUUOF 2mm)»: HHhK NH 1»: mmana hmzm Juuz o: mhumwuum ¢w ~ou4 t H IhXH DNH xm ~m k30hhh~ mtum>wha:u m UDXH ZZZ HJJKQC K C ARE THE LOUER BOUND. INITIAL GUESS AND UPPER BOUND I V E 58 AND PRINT OUT DATA. READ IN UUUUUUUUUUUUUUUUUUUUUUUUUUUU QFPPQGMQELDW QIPUNQITRACERgFPNQGH O.ICN P 9TRUNQITRACER p D X THE DATA IN DINENSIONLESS F0 A 7 v .1 I.» C.- o 0- A 3 '7 H w x 0 1! If) I. P I If) D p.- .l 0 4| A o O '7 \ x v o < a n I D o h D A» O H 2 «ha. H (I. 1‘ tL o Q) 0 EL ’ >2 0 d A 2" >A '3 01-0 2CD v All II C: a up 014a. II— a: a 0:. o- 0- GI 4H“ A .A m a. no: ‘1) AH )— 2.5 o v H o 0.: :II 0': :r 06:).4 ‘Dv'tzh Ln-DP-“C. QVXKQF— GUI/Dd? OXV-IO“! 2303C. (I. 29 0C?- *u2.‘ O h-0 OOOOOHAomomc «canvass Inc» cm aoclt c N Homo—u- pumnfiwt‘fiu In h r- hm QGQHDF’NOZK‘IZ: A n Z O O H F! a“ of «<1 ll H mm 0 P.— A A \C XAr—I AA UXO I‘m >uvx a wee“; o-IlllIYu>-O II o xAAllD-II FAN 3 '- V. O oAI—Az ¥¥¥~¥P Ovvvuvm cxxrmra n SURROUTINE. CALL OPTIMIZATION UUU CALL OPT(NOE,Y,NPA°oBQDELgCHPAXqBNDLUQBNDUPoREDAQRSSTOLoITHAX, ISIS) Fl LL:L.L LIBOFQNOBQNPARI IIoXIMoI). GCVQ?) ) Cp.XEMQ1, .1) pLOT VALUES OF EXPERIMENTAL AND CALCULATED DATA POINTS. UL' UULL.’ CALL PLOTTFR(696095.?Q-N089109IX9IXCNDBQII) CTOR VOLUMES USING TFAR IN SEC AND FLOH IN EA CNS. 60 A F) U 01 \ Q. Q A U A H > >!:IA r- A ‘ II I; O 5" Lo \ L: l- U D U X—ICD 0 m 2)) Ft. < +0 5 0-0 cm. A HX G O\ A > >LJ 0 H3 0 0. fine. w4Ir we) K . ZHOAQCH > O C_J O D 1! ”04: fl OQAu. c In :Dlillch\lf o .-I a. x ... \ '- U; 03 C‘. “(.1qu 2 u :5 GaMA\ufiDa.IAd Oh~n~ Q 0 D “NF“V-Jln “U 0 mm r- 0 .lc~v~¢~Cu-v mun Cl~v N u -marvnaa3 v>v H¢=m3~> II 0 a: mma AC. 1 olc a: z AA‘UNAIDI o<¢An cu 04¢ ‘QI O QAQV O» oflm< OUHmNm< .- g o o~\c new t—H O\ON hr. 41 othCKZI-u—ifi O OFU¢¢> O or- ammaaadca>awm .Idl< FO" Act- 0 oamm 0 >00. «runes It...” unlanACWmfifldl NORWAFTu NQ'fiD m llNhUlIr-In ll t-tlIt-x 0-2 h-svvau: va.rH-<~m: ZP+M1~ IIZO’JL.IICNII¢XZZIZC("(2220- h¢~~>m VUCHh-mvm PO—F‘CIZ ammqu—nau—I—nzzoummmzmoo >Qt~HH¢h>H>>C~¢LkHF>>Qlkb cc. 6‘ \- m 0‘ C‘ 0‘ anMATS.ooo U blias (v.9 C a, A O 3 :IO U OH >- .1\ u.) o o .1.) 0 «Au. 0 PC as O o H h\ o o 7 O c v '2: x \c> o 0. HF) d 0 D C :3 C H \ mu. c Us U o < It a a: c r-r- U) .‘L s LO 0 cv— .1 HI.» _. H3 0 C u lw 0: < Irv. I— HwAd ¢H\C.'I A .- O w 1h- . #063 In 2 O O. I... I...~\02. N 2.“:h o HCH O “AAAGZ\1~ .-I «runny—21 < OOIDOQIH—h OAmDOOX\1 mmu—nau4\ HNOU‘Cfi-ufihdc C-J. wan-mac S: C wwwbvvv. v I—hh+fl-Phwdfih <<<¢<<§ and ff! 11323-5 0:. magnetron-Ice: OOOCCOOLLAC HILILLLKLLL. *h 1:. LSU' QHCJMQU,O v-I OGCICOOG Ca AHAHAHN (\I 61 OCQJu c: own: “X In \Inqm .1 all 1\HZ A Chi-n ‘c 00-! .ntI-x H .umz "O 1‘ lav-daun- OJLOO- H «2:: C c\HU .J O. "(at A Oh. A a o: .u x: If): 0th.] can .o ~04 '\> ILOO o ¢>HC " u. 0. Um I: .- COOLDX “N- In ¢XUHO o 0101! O\ ‘=.Uhh40Akm: ~~n¢2\cxtw Ah. 0 3.1 a 03m X 0034t£\.l ”CKOO (.9002 ' .1). \>I-n in" in, on . O uflOOCOn‘ NAHL‘) on o 2 F. 3.16\£.J< bN‘JU—IACUI- EMF-0.2m! Z HCU 2 02¢ V'IU‘C IO‘IL‘ mam-1:1: 00-410, OOCO-UIHO\U x 00 0.1 U OXXOOUOIOI Fur-€ctzn 0: V'VVVDKOUA v-r-t-t-o—J or-o <<<< 22:23:) at KCGKZ Ham 0 oooco» no.2 LLALLLklILKULLLL ha P F1003. HLIIOO 6H0.) P F1003 . MLIIOO G"O*IQSXQ IE8 62 I I N N G G c c X x \ \ o c Q Q Q Q N N \ \ o o H H 9 9 x X H \ \ o o I N N H H \ \ 2 o o H H H U V "2 a c Q A A “ *' ’I‘ ’I‘ 5 O“ V V U a Q l < z X x g A. U U GU . 0 2 0‘ U A A o~uu~= tx x .. I: I buouo~¢ 2 PF: X xA ZU'U Z \ XUA w. ak ( w A I Utt U C I I- .IIU(¢ c C I ‘ “U I- O ( v K K P- 11 If) 0 I- U D O Oat-I- H U ¢ u a hUmm z I m H 2 A u h m w 0022 U \ u o I- I-n-o 8 AA G A D U I 2 mm A t 4 ¢ U & DKHH A z A .II-Km < II III V 4 U A O OWUU Q U I I c A > mm a 2” U 1 AA A v a o coo L am I m JAZZJJK I z (a V) c: V O HHUU 09 0 IO \ \U U U 3 A: com AA A 06A (I h h EOUWOOU h Ok< 0 A02 b. D 0 JXXIIt Av" PUI m vac UH a o A muzz 3 N0 IQ U \HO 0- t A m D «(mmaA U < 904 D AtA c\A O O O AkbhnnO‘ muho QA¢ J Wh< IAN U. U a QC II>h U0 U. < mUh ~ UIU VIE U4 k v uzoo kw h u can hm cam 2U 6 OD 226 0 RU k AUU A IAc AJU HQ 0 "mat-0"! U) U U IGI U 92 kdI- #0 A o OFUU OD h fl U20 0 AOUAU\ 3: Oh A mummoonn Z A O\H O AOUWI¢O 0 H) m h‘ttUUh> C an omntv I QOOCQOP do an o <¢==mm«\ h OUOC 010kU"UA mz m\ G A meZDDxN m OIh<¢ U ZVPUIUIH an A U U > 2 A oooAh I 0x4 0 Av mm 23 Uta UUUUth O A «GA-Lu h ~~.u~n.1 3 OH X o IIIIOOIO U VA U x UU N C v (1 Au ~\ 0: PPFFZZPM ocu.uuu D U 3HAA\AHU Um m2 22 U v < U uz h UAANUP DH 20 O > mmwwmwm: h NU ¢ a: O h mommmmm U n U UUUUUU UUUUUUUUUUUU UUU - FIJI SAVE THE CALCULATED VALUES FOR PLOTTING. GIJQZ) C C C 64 ozu zanhuz UDZAAZOU on N» o a» u u<¢m + Gaza.aUmcz~I.AXUI.«AU u a» UDZAAZOU A" .H o aulz-\OUU¢ «Uu<¢h Uzh Uh<4304m m C .IO Uttu. X U C2 JvCCO Z x >C A C UU AC h t N z b szCh m on v 0 Debbi: UU r G hummatm 2 hm C H 2 CU H Um U OOZZOQZ Ag 0 o h HH>w( x O A U 2 I 2 U)- N C UCIDUIU U C 10 v a IUUU>OX h a m u Dannnmd o Ahxth C UU O O OmUUUHz :m A A > WMUCU 1 PO C O O UCU O a v w apzzmam L me x U C HHUJF Um a 3 4: HM w bu U uommuam U D h 0 Jxsz I 14 A QKZZFU) D tU o m 3 CC 0 4A co A o thhuUJ OC UO 9 c a czu >H t 0 6 mm A U U U U mzcoz m mv 2U k 0 CO 020 O 0 A4 0 H¢¢HH m #0 A o OPUUA 0 GO A 3A chA Hummua— AA 2 on «an thtCUh h> C K: UH. CKDDCI-C C\ I- on mxca muzzudz ¢N m an hwU > 2 mH zavo UUUUUOU O o Oon IIIIIJIAIO U A H\ t hhhhh FDPH U4 mzz v U DU 200» mmmmmnm wt h 02 Uttm HHHHH H0H¢ C :2 ttth h 3 U D C HOD: AAAAA‘AOAg 4 UI DUUU «NnchOAhh C :U vvvvvhvmvm ) h women m m U UUUUUU UUUUUUUUUUUUUU BIT) A A I ( II HA AA 2 ooUC CCoo AA C AAII than NN ”NNOI tUII we ” HUI-0C (may 3“ (DUIVLD Q. C 1 UV Amm\«<\mAA \\ fl ”HCZHC¢\\ HH C utmflI-CC vv Lt cCUuU\\C\\ UIIZUUIUEOO\DD CIIU OIVNNAOO thCOAO\\\CAA » CC! UHPAAIHN H II .2 'UOD new HNNCV¢ moo~¢¢ A h\ OCCC vv H UCU MIIQ UAHH tUumoo NH QC III UUH—oz U C" HvCAA II 0 CCD II II II II CAN 2 C AAVUU WIICCQIIFPWHN >> Q!" ".1 UUQVVIICC UCZZCCUUUKKGUU O A O A H I X X I 2 v \ A C .— U I .- A O U) A Q. A U X in IO 1 O C ODEL VALUES. p H I PBETAPEIO9A COCI II. II JHPPNDZHO 3 UV DU O UOILOKKOC ADHHDQHOQ C U H UU 66 a:.—ux m cc uzznpzou .ma a» ow .no.«:m4¢\¢»uzbc«pum.zwuooxa an oh co ha o» ow a—.u4.z.u~ ouuooxa . "alum; .n I .<»u1»cqpmm.c|.axw o N» um» .n o .<»u1po<»umaol.axuluh "up w ~¢¢ I t:mc~¢«c.<»uzpc<»umcea.mxu 0 up um» c ~¢¢ o ugOUU¢ zuu<¢h Uzh UhCJbUJCU «fiencofieu u afium thnca Chdo IUCU pzanua ~No5~X\afivuua5~u nooawohnnemu 00¢UN mACDGU h3— uu mur awh<420423 ZXIICZZ HU 0H1 .- nun—:3 ZIICLZI—O onmwouz UI-IL UmU A 0‘ O VII v-I B IBLIOGRAPHY 68 BIBLIOGRAPHY Baker, C. H. "Blood Flow and Volume Distribution with Elevated Venous Pressure." American Journal of Physiology, 218(3):674-680 (March, 1970). Baker, C. H., and Menninger, R. P. "Histamine- induced Peripheral Volume and Flow Changes." American Journal of Physiology, 226(3):731-737 (March, 1974)} Baker, C. H., and Davis, D. L. "Isolated Skeletal Muscle Blood Flow and Volume Changes during Contractile Activity." Blood Vessels, 11:32-44 (1974). Baker, C. H.: Menninger, R. P.: Schoen, R. E.; and Sutton, E. T. "Skeletal Muscle Vascular Volume Changes with Increased Venous Pressure." Blood Vessels, 13:222-237 (1976). Bischoff, K. B., and Dedrick, R. L. "Generalized Solution to Linear, Two-compartment, Open Model for Drug Distribution." Journal of Theoretical Biologx, 29:63-83 (1970). Borghi, M. R. "Mathematical Simulations of Isotope Extractions in Nutritional and Nonnutritional Flow Channels in Vascular Beds." Master's thesis, Michigan State University, 1976. Danckwerts, P. V. "Continuous Flow Systems." Chemical Engineering Science, 2(1):1-13 (Feb., 1953. Friedman, J. J. "Microvascular Flow Distribution and Rubidium Extraction." Federation Proceed- ings, 24:1099-1103 (1965). Friedman, J. J. "Total, Non-Nutritional, and Nutritional Blood Volume in Isolated Dog Hind- limb." American Journal of Physiology, 214(1): 151-156 (1966). 69 70 Friedman, J. J. "Muscle Blood Flow and 86Rb Extrac- tion: 86Rb As a Capillary Flow Indicator." American Journal of Physiology, 214(3):488-493 (I968). Friedman, J. J. "Single-passage Extraction of 86Rb from the Circulation of Skeletal Muscle." American Journal of Physiology, 216(3):460-466 (1969). Goodnight, M. L. Master's thesis, to be published, Michigan State University, 1978. Hamilton, W. F.; Moore, J. W.; Kinsman, J. M.; and Spurling, R. G. "Simultaneous Determination of the Pulmonary and Systemic Circulation Times in Man and of a Figure Related to the Cardiac Output." American Journal of Physiology, 84: 338-344 (1928). Hamilton, W. F.; Moore, J. W.; Kinsman, J. M.; and Spurling, R. G. "Further Analysis of the Injec- tion Method, and of Changes in Hemodynamics Under Physiological and Pathological Conditions." American Journal of Physiology, 99:534-551 (1932). Himmelblau, D. M., and Bischoff, K. B. Process Analysis and Simulation. New York: Jo n Wiley and’Sons, 1968. Levenspiel, 0. Chemical Reaction Engineering. New York: John Wiley and Sons, 1972. Martin, P., and Yudilevich, D. "A Theory for the Quantification of Transcapillary Exchange by Tracer-dilution Curves." American Journal of Physiology, 207(1):l62-168 (1964). Meier, P., and Zierler, K. L. "On the Theory of the Indicator-dilution Method for Measurement of Blood Flow and Volume." Journal of Applied Physiology, 6(12):731-744 (June, 1951). Moore, J. C., and Baker, C. H. "Red Cell and Albumin Flow Circuits During Skeletal Muscle Reactive Hyperemia." American Journal of Physiology, 220(5);121311219 (1971). Mountcastle, V. 8., ed. Medical Physiology. St. Louis: The C. V. Mosby Company, 1974. 21. 22. 23. 24. 25. 26. 27. 28. 29. 71 Naor, P., and Shinnar, R. "Representation and Evaluation of Residence Time Distributions." Industrial andvgngineering Chemistry, Funda- mentals, 2(4):278-286 (1963). Renkin, E. M. "Exchangeability of Tissue Potassium in Skeletal Muscle." American Journal of Physiology, 197(6):1211-I215 (1959). Renkin, E. M. "Transport of Potassium-42 from Blood to Tissue in Isolated Mammalian Skeletal Muscles." American Journal of Physiology, 197(6):1205-1210 (1959). Renkin, E. M., Hudlicka, 0., and Sheehan, R. M. "Influence of Metabolic Vasodilatation on Blood- tissue Diffusion in Skeletal Muscle." American Journal of Physiology, 211(1):87-98 (1966). Renkin, E. M. "Blood Flow and Transcapillary Ex- change in Skeletal and Cardiac Muscle." Int. Symp. on the Coronary Circulation and Energetics of the Myocardium, Milan 1966, pp. 18-30, New York: Karger, Basel, 1967. Zierler, K. L. "Circulation Time and the Theory of Indicator-dilution Methods for Determining Blood Flow and Volume." In Handbook of Physio- logy, Sec. 2 Circulation, Vol 1., Washington, D. C., Am. Physiol. Soc., 1962. Zierler, K. L., M.D. "Theory of Use of Indicators to Measure Blood Flow and Extracellular Volume and Calculation of Transcapillary Movement of Tracers." Circulation Research, 12:464-471 (May, 1963). Zierler, K. L., M.D. "Equations for Measuring Blood Flow by External Monitoring of Radioiso- topes." Circulation Research, 16:309-321 (April, 1965). Zierler, K. L. "Tracer-dilution Techniques in the Study of Microvascular Behavior." Federation Proceedings, 24:1085-1091 (1965).