title: [Mechanisms of NO-dependent relaxation in smooth muscles of the rat aorta with nitro compounds].
abstract: The membrane potential and smooth muscle tension in rat aorta were studied by the method of sucrose gap junction. It was found that sodium nitroprusside and nitroglycerin produced a dose-dependent membrane repolarization and smooth muscle cell relaxation in rat aorta preliminarily contracted and depolarized by hyperpotassium (40 mM) or phenylephrine solutions. The relaxation effect of sodium nitroprusside was more pronounced on the phenylephrine background. The effect of nitroglycerin showed a different kinetics in time and led to the tolerance development. The effects of both nitro compounds were inhibited by pretreatment with Methylene Blue or potassium channel blockers. It is suggested that nitro vasodilators are involved in the NO-dependent processes in smooth muscle cells of aorta through cGMP-mediated activation of the potassium conductivity and by changing the efficiency of operation of the protein kinase C branch of the Ca2+ signal system.
authors.affiliation: Department of Biophysics, Department of Normal Physiology, Siberian Medical University, Moskovskii trakt 2, Tomsk, 634050 Russia.
authors.forename: I V
authors.initials: IV
authors.lastname: Kovalev
authors.forename: A G
authors.initials: AG
authors.lastname: Popov
authors.forename: A A
authors.initials: AA
authors.lastname: Panov
authors.forename: Iu L
authors.initials: IuL
authors.lastname: Borodin
authors.forename: Ia D
authors.initials: IaD
authors.lastname: Afinogenova
authors.forename: L V
authors.initials: LV
authors.lastname: Kapilevich
authors.forename: M B
authors.initials: MB
authors.lastname: Baskakov
authors.forename: M A
authors.initials: MA
authors.lastname: Medvedev
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D002118:Calcium / Q000502:physiology; D006152:Cyclic GMP / Q000502:physiology; D006706:Homeostasis; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials; D009126:Muscle Relaxation; D009129:Muscle Tonus; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D009574:Nitro Compounds / Q000494:pharmacology*; D005996:Nitroglycerin / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D009574:Nitro Compounds; D014665:Vasodilator Agents; D009599:Nitroprusside; D009569:Nitric Oxide; D005996:Nitroglycerin; D006152:Cyclic GMP; D002118:Calcium