title: In vitro characterization of the alpha-adrenoceptors in human prostate.
abstract: The alpha-adrenoceptors of the human prostate gland were characterized in vitro by the use of antagonists selective for alpha 1- and alpha 2-adrenoceptor subtypes. The contractile response induced by norepinephrine in this tissue could be antagonized by prazosin, a selective alpha 1-antagonist, with a receptor dissociation constant (KB) of 4.0 +/- 0.9 nM. The selective alpha 2-antagonists rauwolscine and SK&F 86466 were less potent antagonists of this response, with KB values of 1020 +/- 400 nM and 2400 +/- 800 nM, respectively. The irreversible alpha-antagonists benextramine and phenoxybenzamine, both of which preferentially inactivate the alpha 1-subtype, produced marked depression of norepinephrine-induced contraction. These data would suggest that the alpha-receptors on prostatic smooth muscle are predominantly of the alpha 1-subtype.
authors.forename: J P
authors.initials: JP
authors.lastname: Hieble
authors.forename: M
authors.initials: M
authors.lastname: Caine
authors.forename: E
authors.initials: E
authors.lastname: Zalaznik
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology / Q000627:therapeutic use; D011467:Prostate / Q000032:analysis* / Q000187:drug effects; D011470:Prostatic Hyperplasia / Q000188:drug therapy; D011942:Receptors, Adrenergic, alpha / Q000032:analysis* / Q000187:drug effects
chemical_list: D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha; D009638:Norepinephrine; D011224:Prazosin