title: Nitroxidergic innervation in dog and monkey renal arteries.
abstract: We analyzed mechanisms underlying neurogenic vasodilatation in dog and Japanese monkey renal arteries. Isometric mechanical responses of the arterial strip to nerve stimulation by nicotine were recorded. Nicotine-induced contractions were abolished by hexamethonium and potentiated by NG-nitro-L-arginine, a nitric oxide synthase inhibitor. The potentiating effect was reversed by L-arginine. NG-Nitro-L-arginine did not potentiate the contraction caused by norepinephrine. The nicotine-induced contraction was reversed to a relaxation by prazosin. The relaxation was not influenced by indomethacin, timolol, or atropine but was abolished by NG-nitro-L-arginine, methylene blue (a guanylate cyclase inhibitor), oxyhemoglobin (a nitric oxide scavenger), and hexamethonium. In the strips treated with NG-nitro-L-arginine, the nicotine-induced relaxation was restored by L-arginine. Histochemical study demonstrated perivascular nerves containing NADPH diaphorase and nitric oxide synthase immunoreactivity in dog and monkey arteries. We conclude that renal arteries are innervated by nitric oxide-mediated vasodilator and adrenergic vasoconstrictor nerves, and depression of the vasodilator nerve function by nitric oxide synthase inhibition potentiates the contraction caused by adrenergic nerve excitation.
authors.affiliation: Department of Pharmacology, Shiga University of Medical Sciences, Ohtsu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okamura
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: N
authors.initials: N
authors.lastname: Toda
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D008251:Macaca; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine; D012077:Renal Artery / Q000294:innervation* / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D019335:Nitroarginine; D009569:Nitric Oxide; D009538:Nicotine; D001120:Arginine