title: Contractile response of horse deep dorsal penile vein to histamine.
abstract: The present investigation was designed to evaluate the effect of histamine on isolated rings of horse deep dorsal penile vein. Under precontracted or basal conditions, histamine evoked an endothelium-independent contraction. Preincubation of the vein rings with the selective H1 receptor antagonist, mepyramine, shifted the concentration-response curve for histamine and to the H1 receptor agonist 2-pyridylethylamine to the right in a competitive manner. Pretreatment with cimetidine, a specific H2 receptor antagonist, did not modify the pEC50 and maximal contraction of the histamine response. Cimetidine and propranolol failed to induce a change in the relaxation caused by dimaprit, the H2 receptor agonist. Histamine contraction was unaffected by thioperamide, the specific H3 receptor antagonist. (R)-alpha-methylhistamine, the H3 receptor agonist, also induced contractions which persisted in the presence of either thioperamide or tetrodotoxin. These data indicate that horse deep dorsal penile vein shows an endothelium-independent contraction response to histamine, mainly mediated by H1 receptors.
authors.affiliation: Sección Departamental de Fisiología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
authors.forename: A C
authors.initials: AC
authors.lastname: Martínez
authors.forename: D
authors.initials: D
authors.lastname: Prieto
authors.forename: M
authors.initials: M
authors.lastname: Hernández
authors.forename: A
authors.initials: A
authors.lastname: García-Sacristán
authors.forename: S
authors.initials: S
authors.lastname: Benedito
mesh_terms: D000818:Animals; D006632:Histamine / Q000494:pharmacology*; D017442:Histamine Agonists / Q000494:pharmacology; D006633:Histamine Antagonists / Q000494:pharmacology; D006736:Horses; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D010413:Penis / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism; D011968:Receptors, Histamine / Q000378:metabolism; D014680:Veins / Q000187:drug effects
chemical_list: D017442:Histamine Agonists; D006633:Histamine Antagonists; D011968:Receptors, Histamine; D006632:Histamine