Endothelin stimulates angiotensin I to angiotensin II conversion in cultured pulmonary artery endothelial cells.
We studied the effects of endothelin on the conversion of angiotensin I to angiotensin II in pulmonary artery endothelial cells. Endothelin had a novel effect on angiotensin I conversion. When endothelin was added to pulmonary artery endothelial cells, the conversion of angiotensin I to angiotensin II was enhanced about two-fold. The maximum stimulation was achieved at 10(-8) M of endothelin. This stimulatory effect was suppressed by angiotensin converting enzyme inhibitors such an enalapril. When the calcium antagonist, nifedipine, was incubated with 10(-8) M of endothelin, the conversion of angiotensin I to angiotensin II stimulated with endothelin was slightly suppressed by nifedipine. Enalapril (10(-6) M) completely inhibited the conversion of angiotensin I to angiotensin II in the presence of endothelin. These results suggest that endothelin may play an important role in regulating vascular tone by modulating the conversion of angiotensin I to angiotensin II.
Kawaguchi
H
H
Department of Cardiovascular Medicine, Hokkaido University, School of Medicine, Sapporo, Japan.
Sawa
H
H
Yasuda
H
H
D000803:Angiotensin I / Q000378:metabolism*; D000804:Angiotensin II / Q000096:biosynthesis*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D004656:Enalapril / Q000494:pharmacology; D016232:Endothelins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D011651:Pulmonary Artery / Q000187:drug effects* / Q000378:metabolism; D013268:Stimulation, Chemical
D000806:Angiotensin-Converting Enzyme Inhibitors; D016232:Endothelins; D000804:Angiotensin II; D004656:Enalapril; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D009543:Nifedipine; D002118:Calcium