Electron microscopy showed that structure of the endothelial cells in pulmonary arterioles in group HC was near to normal,and the proliferation of medial smooth muscle cells and collagen fibers in adventitia was much lighter than those of group HH.

• 电镜下,HH组肺细小动脉中膜平滑肌细胞增生,面积增大,染色质增多,外膜胶原纤维密集,HC组大鼠肺细小动脉内皮细胞结构基本正常,胶原少见,中膜平滑肌细胞和外膜胶原纤维增生较HH组明显为轻;