Inhibitory effects of L-NG-nitro-arginine on the synthesis of EDRF and the cerebroarterial response to vasodilator nerve stimulation.
Treatment with L-NG-nitro-arginine (L-NA) inhibited the brady-kinin-induced relaxation, mediated via EDRF, in dog coronary artery strips partially contracted with prostaglandin F2 alpha; the inhibition was prevented by L-, but not D-, arginine. Relaxation caused by nitroglycerin was not altered by L-NA. The release of EDRF, as assayed using dog coronary artery strips without endothelium, from perfused femoral artery segments with endothelium in response to acetylcholine and substance P was significantly reduced by treatment of the femoral artery with L-NA. The inhibitory effect was reversed by L-arginine. Relaxant responses of dog cerebral artery strips with and without endothelium to electrical stimulation of non-adrenergic, non-cholinergic nerves were suppressed by L-NA, whereas relaxation of coronary arteries with and without endothelium by the stimulation of adrenergic nerves was not influenced. The L-NA-induced inhibition was reversed by L-arginine. It is speculated that L-NA inhibits the synthesis of EDRF, as does L-NG-monomethyl arginine, and NO-like substance(s) produced plays an important role in transferring information from vasodilator nerves to smooth muscle in cerebral arteries.
Toda
N
N
Department of Pharmacology, Shiga University of Medical Sciences, Ohtsu, Japan.
Minami
Y
Y
Okamura
T
T
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology; D002536:Cerebral Arteries / Q000294:innervation* / Q000502:physiology; D003331:Coronary Vessels / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D015237:Dinoprost / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000294:innervation; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000378:metabolism; D019335:Nitroarginine; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D015237:Dinoprost; D001920:Bradykinin