Alpha-adrenergic blockers on ventricular automatism in rat heart

Abstract

The role of the alpha-adrenergic receptors in the genesis of cardiac arrhythmias induced in the isolated rat right ventricle has been studied. The administration of six alpha-adrenergic blocking agents (phenoxybenzamine, dibenamine, phentolamine, tolazoline, azapetine and SY-28) did not alter the automatism induced. Even when can not be excluded the existance of alpha-adrenergic receptors in the rat ventricle, it is clear that alpha-blocking drugs are ineffective to abolish the arrhythmias induced by an increase in the activity of the Purkinje fibers.