Pulmonary hypertension (PH) is associated with elevated pulmonary arterial pressure. PH prognosis remains poor with 15% mortality rate within 1 year even with modern clinical managements. Previous clinical studies proposed the wall shear stress (WSS) to be an important hemodynamic factor for affecting cell mechanotransduction and growth and remodeling in the disease progress. However, a typical range of WSS in vivo is at most 2.5 Pa and a doubt has been casted whether WSS alone can influence the disease progress. Furthermore, our current understanding of PH pathology has largely been obtained through small animals and there has been seldom reports of caliber enlargement in the PH animal models. Therefore, a large-animal experiment on pulmonary arteries (PAs) is needed for validating whether an increased pressure can induce an enlargement of pulmonary caliber. In this study, we use an inflation testing device to characterize the mechanical behavior, both nonlinear elastic behavior and irreversible damage of porcine arteries. The parameters of elastic behavior are estimated from the inflation test at a low-pressure range first and then are compared with those from a high-pressure range, which tests if those behavior are significantly different. At the end of mechanical tests, histological images are qualitatively examined for medial and adventitial layers. This study, therefore, sheds light on the relevance of pressure-induced damage mechanism in human PH.
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