Sims F H, Koelmeyer T D, Zhang Y P, Lambie N, Edgar S G
Department of Pathology, Auckland University School of Medicine, New Zealand.
Exp Lung Res. 1995 May-Jun;21(3):367-83. doi: 10.3109/01902149509023714.
Lung tissue from subjects dying from primary plexogenic pulmonary hypertension (PPH) has shown defects of elastin formation of the lung arteries. Lung vessels from 5 cases of PPH were compared with those of 9 age-matched normal subjects, and 24 individuals having secondary pulmonary hypertension (2 degrees PH). PPH cases and those with 2 degrees PH due to congenital heart disease with left-to-right shunts (2 degrees PH, LRS), showed active proliferation of medial smooth muscle cells (SMC) through defects of the internal elastic lamina (IEL) into the arterial lumen to form typical plexiform lesions. Larger arteries showed accelerated intimal thickening similar to normal aging. Plexiform lesions were not seen in normal subjects or in those developing high pulmonary pressures later in life. The observations showed that the development of discontinuities of the IEL of the pulmonary arteries and intimal thickening is accelerated in normal subjects by high pulmonary artery pressure, especially when this is established at a very young age. They suggest that such discontinuities occur in PPH due to inherent abnormality of the elastin of the arterial walls, with advanced early proliferation of medial SMC and obstruction of the pulmonary arterial circulation.
死于原发性丛状肺动脉高压（PPH）的受试者的肺组织显示出肺动脉弹性蛋白形成缺陷。将5例PPH患者的肺血管与9例年龄匹配的正常受试者以及24例继发性肺动脉高压（2级PH）患者的肺血管进行比较。PPH病例以及因先天性心脏病伴左向右分流导致的2级PH（2级PH，LRS）患者，显示出中层平滑肌细胞（SMC）通过内弹性膜（IEL）缺陷向动脉腔的活跃增殖，形成典型的丛状病变。较大的动脉显示出类似于正常衰老的内膜增厚加速。正常受试者或晚年出现高肺压的受试者中未见丛状病变。观察结果表明，在正常受试者中，肺动脉IEL的连续性中断和内膜增厚的发展会因高肺动脉压而加速，尤其是在非常年轻时就出现这种情况。他们认为，这种连续性中断在PPH中是由于动脉壁弹性蛋白的固有异常、中层SMC的早期增殖以及肺动脉循环的阻塞所致。
