实验性缺氧性肺动脉高压肺腺泡内动脉的超微结构观察

目的:观察实验性缺氧性肺动脉高压肺腺泡内动脉的超微结构变化并探讨其发生机理。方法:将Wistar大鼠随机分成对照组(n=9)及肺动脉高压组(n=9)。以右心导管法测定肺动脉平均压力(mPAP)。用透射电镜观察肺腺泡内动脉超微结构。结果:肺动脉高压组大鼠mPAP较对照组明显增高(P<0 01)。超微结构观察,肺动脉高压组大鼠肺腺泡内动脉内皮细胞增生、变性。内弹力膜厚薄不均。呼吸性细支气管水平小动脉中层平滑肌细胞增生;呼吸性细支气管水平及肺泡水平小动脉肌化。中间型细胞及血管周细胞增生。胶原原纤维增多。结论:肺腺泡内动脉平滑肌细胞增生及动脉肌化是缺氧性肺动脉高压特征性的超微结构变化。肺血管结构重建是缺氧性肺动脉高压形成的病理基础。

Ultrastructural observation of intra-acinar pulmonary arteries on experimental hypoxic pulmonary hypertesion

Objective: To observe ultrastructural changes of intra-acinar pulmonary arteries and study the pathogenesis of experimental hypoxic pulmonary hypertension.Methods: Wistar rats were randomly divided into control groups(n=9)and pulmonary hypertension groups(n=9).Mean Pulmonary artery Pressure(mPAP)of each rat was evaluated using a right cardiac Catheterization procedure.Ultrastructure of intra-acinar pulmonary arteries was observed by transmission electron microscope.Results: The mPAP was significantly higher in rats of pulmonary proliferation and degeneration hypertension group than that of control group(P<0.01).Ultrastructrural observation showed the proliferation and degeneration of endothelial cells in intra-acinar pulmonary arteries on pulmonary hypertension group.The internal elastic laminar was irregular.The proliferation of medial smooth muscle cells of arteries was showed at the level of respiratory bronchioles.The muscularized arteries were observed at the level of both respiratory bronchioles and alveoli.The hyperplasia of intermediate cells and pericytes was present.The collagens increased.Conclusions: The proliferation of smooth muscle cells and arterialization of intra-acinar pulmonary arteries are characteristic ultrastructural changes of hypoxic pulmonary hypertension.The results indicate that pulmonary vascular structural remodeling is the important pathologic basis of hypoxic pulmonary hypertension.