L-NG-monomethyl arginine inhibits the vasodilating effects of low dose of endothelin-3 on rat mesenteric arteries.
We have reported that low doses of endothelin-3 (ET-3) elicited continuous vasodilation of rat mesenteric arteries, which is possibly related to endothelium-derived relaxing factor (EDRF). In order to clarify whether or not the vasodilating effects of ET-3 are associated with EDRF, we examined the effects of L-NG-monomethyl arginine (L-NMMA), an analog of L-arginine, on low-dose ET-3 induced vasodilation of rat mesente-Hc arteries. Infusion of 50 microM L-NMMA inhibited the vasodilation induced by 10(-13) M ET-3 and rather elicited an increase in perfusion pressure, which itself was decreased by infusion of 150 microM L-arginine. In the presence of 50 microM L-NMMA, 10(-13) M ET-3 did not elicit any vasodilation of the mesenteric arteries preconstricted with NE, in which 150 microM L-arginine, but not D-arginine, caused considerable vasodilation. These data suggest that the vasodilating effects of low doses of ET-3 are associated with EDRF as an endothelium-derived nitric oxide.
Fukuda
N
N
2nd Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan.
Izumi
Y
Y
Soma
M
M
Watanabe
Y
Y
Watanabe
M
M
Hatano
M
M
Sakuma
I
I
Yasuda
H
H
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016232:Endothelins; D004730:Endothelium, Vascular / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010455:Peptides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010477:Perfusion; D011312:Pressure; D051381:Rats; D011919:Rats, Inbred Strains; D014664:Vasodilation / Q000187:drug effects*; D019323:omega-N-Methylarginine
D016232:Endothelins; D010455:Peptides; D019323:omega-N-Methylarginine; D001120:Arginine; D009638:Norepinephrine