NG-monomethyl-L-arginine and NG-nitro-L-arginine inhibit endothelium-dependent relaxations in human isolated omental arteries.
The L-arginine analogues NG-monomethyl-L-arginine (L-NMMA, 10(-4) M) and NG-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), which specifically inhibit the synthesis of nitric oxide from L-arginine, significantly reduced acetylcholine-induced endothelium-dependent relaxations in rings of human omental arteries. The inhibitory potency of L-NMMA and L-NAME was similar. Addition of L-NMMA or L-NAME to the organ bath did not induce any significant changes in the resting tension of the tissues. The effects of L-NMMA were reversed by L-arginine (3 x 10(-4) M). The L-NMMA enantiomer, D-NMMA (10(-4) M), did not influence either the basal tone of the preparation or the relaxing effects of acetylcholine. Arterial relaxations induced by sodium nitroprusside (10(-6) M) were not influenced by incubation with L-NMMA or L-NAME. These results suggest that endothelium-dependent relaxations in human omental arteries are mediated by the endogenous and substrate-specific generation of nitric oxide from L-arginine.
Department of Physiology, University of Valencia, Spain.
J
J
Vila
J V
JV
Esplugues
M A
MA
Martinez-Cuesta
M C
MC
Martinez-Martinez
M
M
Aldasoro
B
B
Flor
S
S
Lluch
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001158:Arteries / Q000187:drug effects; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000378:metabolism; D009852:Omentum / Q000098:blood supply; D012039:Regional Blood Flow / Q000187:drug effects; D019323:omega-N-Methylarginine
D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester