title: Moderate hypothermia attenuates α1-adrenoceptor-mediated contraction in human varicose spermatic vein: The role of nitric oxide(Short communication).
abstract: The effects of moderate hypothermia (28 °C) on the response of human varicose spermatic vein to α1-adrenoceptor agonist phenylephrine and the role of endothelial nitric oxide (NO) in these effects were studied. Concentration-response curves for phenylephrine (10-9to 3 × 10-4M) were recorded in rings with and without endothelium at 37 and 28 °C. To further analyze the role of NO, in the response to phenylephrine during hypothermia, the effects of this agonist in the presence of NG-nitro-L-arginine methyl ester (10-4M) were also determined. Under every condition tested, phenylephrine produced a marked, concentration-dependent contraction. Sensitivity of intact veins to the agonist was consistently lower at 28 °C than at 37 °C. There was no significant difference in phenylephrine response at 28 and 37 °C in vessels without endothelium but at 28 °C veins without endothelium showed a higher sensitivity than intact veins to phenylephrine. The sensitivity of veins with and without endothelium to nitroprusside (10-9to 3 × 10-3M) was significantly decreased during hypothermia, and endothelium removal did not affect the relaxation to this nitrovasodilator. These results suggest that moderate hypothermia decreases the sensitivity of human varicose spermatic vein to phenylephrine probably by increasing the availability of endothelial NO.
authors.affiliation: 1 Department of Pharmacology, Meram Faculty of Medicine, Necmettin Erbakan University , Konya, Turkey.
authors.forename: K E
authors.initials: KE
authors.lastname: Nurullahoglu-Atalik
authors.affiliation: 2 Department of Urology, Medline Hospital , Konya, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Cenker
mesh_terms: D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007036:Hypothermia, Induced; D066298:In Vitro Techniques; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction; D013085:Spermatic Cord / Q000098:blood supply*; D014646:Varicocele / Q000378:metabolism* / Q000503:physiopathology; D014648:Varicose Veins / Q000378:metabolism* / Q000503:physiopathology; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D014680:Veins / Q000378:metabolism* / Q000503:physiopathology
chemical_list: C547713:ADRA1A protein, human; D058646:Adrenergic alpha-1 Receptor Agonists; D004791:Enzyme Inhibitors; D018340:Receptors, Adrenergic, alpha-1; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester
keywords: NO; endothelium; hypothermia; phenylephrine; spermatic vein; temperature