[Effect of L-arg and SNP on pulmonary arterial pressure and vascular structural changes of chronically hypoxic rats]

The effects of L-arginine (L-arg) and sodium nitroprusside (SNP) on pulmonary arterial pressure, the percentage of muscularization of intra-acinar vessels and ultrastructural changes of extra pulmonary artery and pulmonary arteriole of chronically hypoxic rats were studied. The results showed that: (1) Both L-arg and SNP decreased mean pulmonary arterial pressure of chronically hypoxic rats significantly. (2) Both L-arg and SNP reduced the percentage of muscularization of intra-acinar vessels of chronically hypoxic rats significantly. (3) Both L-arg and SNP protected pulmonary artery from the damages of endothelium and the changes in smooth muscle cell phenotype by hypoxia. These results suggested that exogenous nitric oxide might play a role in the protection of pulmonary arterial function and structure which alleviate the development of pulmonary hypertension induced by chronic hypoxia.