title: Amplifying effects of several vasoconstrictor agents of alpha 1-adrenoceptor-mediated contraction of isolated thoracic aortae of the guinea pig.
abstract: In guinea-pig aorta phenylephrine and noradrenaline induced concentration-dependent contractions when beta-adrenoceptors were blocked. The contractile response to phenylephrine was amplified by previous application of subthreshold concentrations of 5-hydroxytryptamine, ouabain, B-HT 920, Bay K 8644, phorbol-12-myristate-13-acetate and arachidonic acid. Bay K 8644 also enhanced the contractile response to noradrenaline. The amplification was not substantially altered by removing the endothelium of the aorta. The increase in cytosolic calcium availability induced by the vasoconstrictor agents investigated may be responsible for the enhancement of the alpha 1-adrenoceptor-mediated contractions.
authors: Pharmakologisches Institut, Universitätsklinikum Essen, BRD.
authors: G J
authors: GJ
authors: Molderings
authors: H J
authors: HJ
authors: Schümann
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000502:physiology*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000502:physiology; D006168:Guinea Pigs; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D001095:Arachidonic Acids; D001381:Azepines; D011942:Receptors, Adrenergic, alpha; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D016718:Arachidonic Acid; D012701:Serotonin; D010042:Ouabain; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C024763:talipexole; D013755:Tetradecanoylphorbol Acetate; D009638:Norepinephrine