[Impact of nitric oxide on endothelin gene expression in intrapulmonary arteries of chronic hypoxic rats].
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
Nitric oxide inhibited ET gene expression in both pulmonary artery endothelial cells and smooth muscle cells of rats exposed to chronic hypoxia.
Du
J
J
Department of Pediatrics, First Hospital, Beijing Medical University.
Li
W
W
Zhao
B
B
Li
W
W
D000818:Animals; D002908:Chronic Disease; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D000860:Hypoxia / Q000235:genetics*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar
D019332:Endothelin-1; D012333:RNA, Messenger; D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester