title: Effect of moderate cooling on contractile responses in mouse vas deferens and its relation to calcium.
abstract: Isolated mouse vas deferens preparations were used to study the effect of temperature on noradrenaline-induced contractions. Preparations were suspended in the organ bath containing Krebs-Henseleit solution for isometric tension recording. Contractile responses to noradrenaline were investigated in the mouse vas deferens after moderate cooling from 37 to 26 or 22 degrees C. A significant increase of the phasic contractions to noradrenaline was observed at 26 or 22 degrees C compared with responses obtained at 37 degrees C (about 12.3 and 35.6% increase at 26 and 22 degrees C, respectively). The secondary noradrenaline-induced sustained contraction was also significantly enhanced after moderate cooling to 26 degrees C. The potentiation of noradrenaline-induced contraction at 26 degrees C remained in a Ca(2+)-free EGTA (1 mM)-containing solution. However, sustained contraction was suppressed after removal of the calcium from the medium at 37 and 26 degrees C. Contraction to caffeine was significantly enhanced at 22 degrees C compared with 37 degrees C. By contrast, barium chloride-induced contraction of the vas deferens was markedly decreased after moderate cooling to 22 degrees C. In the presence of ouabain (0.1 mM), the noradrenaline-induced peak contraction was significantly increased at 37 degrees C. However, potentiation of the noradrenaline response at 22 degrees C was unaffected by the Na+/K+ pump inhibitor. Noradrenaline-induced peak contractions were depressed in the presence of vanadate (1 mM) and cyclopiazonic acid (10 microM), two Ca(2+)-ATPase inhibitors, at 37 degrees C and also at 22 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratoire de Physiologie et Pharmacodynamie, Ecole Nationale Veterinaire, Nantes, France.
authors.forename: O
authors.initials: O
authors.lastname: Souilem
authors.forename: J C
authors.initials: JC
authors.lastname: Bidon
authors.forename: M
authors.initials: M
authors.lastname: Gogny
authors.forename: M
authors.initials: M
authors.lastname: Blin
authors.forename: A T
authors.initials: AT
authors.lastname: Vu
authors.forename: A
authors.initials: A
authors.lastname: Jondet
mesh_terms: D000818:Animals; D017609:Barium Compounds / Q000494:pharmacology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002712:Chlorides / Q000494:pharmacology; D003080:Cold Temperature; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
chemical_list: D017609:Barium Compounds; D002712:Chlorides; D004791:Enzyme Inhibitors; D007211:Indoles; C024986:barium chloride; D002110:Caffeine; D014638:Vanadates; D010042:Ouabain; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium; D009638:Norepinephrine; C000543:cyclopiazonic acid