Alpha-adrenergic blockers on ventricular automatism in rat heart.
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.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D011690:Purkinje Fibers / Q000502:physiology*; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D013268:Stimulation, Chemical; D016276:Ventricular Function
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D011942:Receptors, Adrenergic, alpha