新生乳猪缺氧性肺动脉高压的肺血管重构

目的：探讨缺氧性肺动脉高压新生乳猪血管形态学的变化。方法：42只新生乳猪分成正常发育组和缺氧性肺动脉高压组。其中20只新生乳猪置于低气压仓中3或11d形成不同程度缺氧性肺动脉高压模型。采用免疫组化方法和γ－肌动蛋白抗体染色对肺小动脉的形态学变化进行定量分析。结果：正常新生乳猪出生后早期随着日龄增加，血管壁中层百分率快速下降；缺氧抑制了中层厚度百分率的下降，甚至增加这种百分率（P＜0．01），同时中层与管腔面积比值与中层百分率有相同的变化倾向。结论：新生乳猪出生后肺血管快速重构以适应子宫外生活环境。缺氧及缺氧性肺动脉高压改变正常肺血管的重构，导致或加重肺动脉高压。

Pulmonary vascular remodeling in hypoxic hypertension in newborn pigs]

OBJECTIVE: To determine the pulmonary vascular morphologic changes in small pulmonary arteries of normal development and hypoxic hypertension in newborn pigs. METHODS: Forty-two pigs aged from the birthday to 14 days were divided into the normal developmental group and hypoxic hypertensive group. Twenty of them were exposed to hypobaric hypoxia (50.8 kPa) for 3 or 11 days to establish a pulmonary hypertension model. With the immunohistochemistric method and tissue slices stained with gamma-actin antibody, small pulmonary artery morphologic changes were analyzed. RESULTS: In the normal newborn pigs, the percentage of media thickness decreased rapidly; and the ratio of the media area to the lumen area also decreased rapidly during the first 6 days after birth. Hypoxia weakened the decrease of the media thickness percentage and the ratio of the media area to the lumen area during the early period after birth. CONCLUSION: To adapt to the extrauterine life, newborn pigs rapidly remodel pulmonary blood vessels after birth. Hypoxia and hypoxic hypertensions induce abnormal pulmonary vascular remodeling causing pulmonary artery hypertension or making it serious.