Depressant effects of phenoxygenzamine on potassium contracture in cat ventricular muscle.
Phenoxybenzamine has been shown to have a depressant action on K+-depolarization contracture in cat ventricular muscle. In the present study, we show that this depressant action is specific for phenoxybenzamine and occurs in the presence of beta-adrenergic receptor blockade with nadolol. K+-contracture is not depressed by phentolamine nor augmented by phenylephrine. Thus, the depressant action of phenoxybenzamine is not mediated by its effects on cardiac adrenergic receptors.
D000818:Animals; D002415:Cats; D003864:Depression, Chemical; D004347:Drug Interactions; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D010643:Phenoxybenzamine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D010643:Phenoxybenzamine; D011188:Potassium; D010646:Phentolamine