Impact of nitric oxide on endothelin gene expression in intrapulmonary arteries of chronic hypoxic rats
Du, J.; Li, W.; Zhao, B.; Li, W.
Zhonghua Yi Xue Za Zhi 77(4): 263-265
1997
ISSN/ISBN: 0376-2491 PMID: 9596925 Document Number: 476245
To investigate the impact of nitric oxide on endothelin-1 (ET-1) mRNA expression in pulmonary artery endothelial cells and pulmonary artery smooth muscle cells of chronic hypoxic rats. In situ hybridization was performed on lung sections from 40 chronic hypoxic rats treated either with L-Arginine (L-Arg) or N omega-nitro-L-arginine methyl ester (L-NAME) by using cRNA probe for ET-1. Most intrapulmonary arteries had 1%-50% of the endothelial cells expressing ET-1 mRNA in both one-week and two-week hypoxic rats (75% +/- 3% and 71% +/- 6%, respectively), which was significantly inhibited by L-Arg but augmented by L-NAME administration. Most pulmonary artery smooth muscle cells showed no ET-1 mRNA signals in both one-week and two-week hypoxic rats (85% +/- 6% and 98% +/- 2%, respectively). However, L-NAME increased ET-1 mRNA expression in pulmonary artery smooth muscle cells of hypoxic rats. Nitric oxide inhibited ET gene expression in both pulmonary artery endothelial cells and smooth muscle cells of rats exposed to chronic hypoxia.