title: Role of the nitric oxide on relaxation of the human umbilical artery during cooling.
abstract: In the present study, the effects of cooling (to 28°C) on the vasodilatation induced by diazoxide (10(-9)-3×10(-4) M), isoproterenol (10(-9)-3×10(-4) M) and magnesium sulphate (0.1-30 mM) on serotonin-pre-contracted human umbilical artery and the role of nitric oxide in these effects were analyzed. Diazoxide, isoproterenol and magnesium produced concentration-dependent relaxation of human umbilical artery precontracted with serotonin (10(-6) M). During cooling, the pIC(50) values and maximal responses to these agents were significantly lower than at 37°C. Cooling to 28°C in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) did not modify the effects of temperature on diazoxide, isoproterenol and magnesium-induced relaxations. These results suggest that cooling-induced changes of diazoxide, isoproterenol, and magnesium sulphate in human umbilical artery are independent of nitric oxide.
authors.affiliation: Department of Pharmacology, Faculty of Meram Medicine, University of Selçuk, Konya, Turkey. esraatalik@hotmail.com
authors.forename: K E
authors.initials: KE
authors.lastname: Nurullahoğlu Atalik
authors.forename: Z U
authors.initials: ZU
authors.lastname: Nurullahoğlu
authors.forename: M
authors.initials: M
authors.lastname: Kiliç
mesh_terms: D003080:Cold Temperature; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008278:Magnesium Sulfate / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D014469:Umbilical Arteries / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D009569:Nitric Oxide; D012701:Serotonin; D008278:Magnesium Sulfate; D007545:Isoproterenol; D019331:NG-Nitroarginine Methyl Ester