title: Involvement of NK receptors and beta-adrenoceptors in nitric oxide-dependent relaxation of rabbit aorta rings following electrical-field stimulation.
abstract: Electrical-field stimulation caused an endothelium-dependent relaxation in rabbit aorta rings precontracted by phenylephrine. The relaxation was reduced in a dose-dependent manner by morphine, benzalkonium, [D-Pro2,D-Trp7,9]substance P and an beta-adrenoceptor antagonist, propranolol. The vasodilatation was enhanced by superoxide dismutase and abolished by haemoglobin and NG-monomethyl-L-arginine. The inhibitory effect of NG-monomethyl-L-arginine was reversed by L-arginine, the precursor of nitric oxide biosynthesis, but not by its enantiomer, D-arginine. These data show that the electrically induced relaxation is independent on nitric oxide released by NK receptors and beta-receptors. Moreover, morphine, by reducing substance P release, decreased the magnitude of electrically induced relaxation, suggesting an indirect role of opioids in the regulation of the peripheral circulation through the control of nitric oxide release. Furthermore our observations confirm the hypothesis that subtypes of beta-adrenoceptors releasing nitric oxide participate in the regulation of vascular tone.
authors.affiliation: Department of Experimental Pharmacology, University of Naples Federico II, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Persico
authors.forename: A
authors.initials: A
authors.lastname: Calignano
authors.forename: F
authors.initials: F
authors.lastname: Mancuso
authors.forename: L
authors.initials: L
authors.lastname: Sorrentino
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001548:Benzalkonium Compounds / Q000494:pharmacology; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism*; D010656:Phenylephrine / Q000494:pharmacology; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D018039:Receptors, Tachykinin / Q000187:drug effects / Q000502:physiology*; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D019323:omega-N-Methylarginine
chemical_list: D000319:Adrenergic beta-Antagonists; D001548:Benzalkonium Compounds; D011943:Receptors, Adrenergic, beta; D018039:Receptors, Tachykinin; D010656:Phenylephrine; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D013373:Substance P; D009020:Morphine; D001120:Arginine