Influence of NG-monomethyl-L-arginine on endothelium-dependent relaxations in the perfused mesenteric vascular bed of the rat.
Endothelium-dependent relaxation mediated by the formation of nitric oxide (NO) from L-arginine, is prevented by the arginine analog NG-monomethyl L-arginine (L-NMMA) (Palmer et al., Biochem. Biophys. Res. Comm. 153:1251-1256 (1988)). In the rat mesenteric arterial bed, incubation with L-NMMA did not prevent acetylcholine-induced relaxation, which, however, was reversed when L-NMMA was added during its maximum effect. A similar profile of action was observed with methylene blue, an inhibitor of guanylate cyclase. Methylene blue, but not L-NMMA, increased basal perfusion pressure. These data indicate that in the mesenteric arterial bed, NO formation via the L-NMMA-sensitive pathway occurs during stimulation with acetylcholine, but not under basal conditions.
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Cardiovascular Research Department, CIBA-GEIGY Limited, Basel, Switzerland.
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D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000502:physiology*; D066298:In Vitro Techniques; D008638:Mesenteric Arteries; D008751:Methylene Blue / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014664:Vasodilation / Q000187:drug effects*; D019323:omega-N-Methylarginine
D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D000109:Acetylcholine; D008751:Methylene Blue