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 β-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.
- Potassium contracture
- Ventricular muscle
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience