A MORPHOLOGICAL STUDY ON PULMONARY VASCULAR RESPONSE TO UNILATERAL HYPOXIA IN GUINEA PIG

Abstract

In 1946,Euler reported pulmonary arterial hypertension occurred through induction of alveolar hypoxia in cats. In his report, Euler attributed the pressure rise to constriction of pulmonary vascular bed. Although a large number of studies have been done on this problem since then, no clear-cut evidence for pulmonary vascular constriction have been obtained so far, mainly due to lack of proper experimental methods. In 1962,Staub reported rapid freezing method of the lung with liquid propane or liquid nitrogen for the purpose of visualizing the pulmonary circulatory hemodynamics on morphological base. Utilizing his method, we designed an experiment to solve a few problems on the reactivity of pulmonary vascular bed of guinea pig as follows. -1) Whether hypoxic stimulus can actually induce constriction of pulmonary vascular bed or not? 2) Site of constriction within the vascular bed, if the constriction can be induced by hypoxia. 3) The mechanism of constriction.