title: Regulation of the adenylate cyclase system by catecholamines in the rat prostate.
abstract: Tolerance to catecholamines in the beta-adrenergic and dopaminergic receptor-adenylate cyclase system from the rat prostatic membrane has been studied. Preincubation of the tissue with isoproterenol produced not only a decrease in beta-adrenergic receptors and its sensitive adenylate cyclase activity, but also a reduction in dopaminergic response. Similarly, exposure to dopamine resulted in a decline both of isoproterenol- and dopamine-stimulated adenylate cyclase activity. A beta adrenergic antagonist, propranolol, exclusively blocked desensitization in the beta-adrenergic and dopaminergic adenylate cyclase system caused by isoproterenol, while dopamine-induced refractoriness was prevented by a dopaminergic antagonist, haloperidol. These results suggest that desensitization of the beta-adrenergic and dopaminergic adenylate cyclase system begins on receptor-occupation by its specific agonist.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002395:Catecholamines / Q000502:physiology*; D004082:Dihydroalprenolol; D004298:Dopamine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008566:Membranes / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D011467:Prostate / Q000201:enzymology / Q000502:physiology*; D051381:Rats
chemical_list: D002395:Catecholamines; D004082:Dihydroalprenolol; D011433:Propranolol; D000262:Adenylyl Cyclases; D006220:Haloperidol; D007545:Isoproterenol; D004298:Dopamine