Failure of beta-adrenergic receptor blockade to prevent arrhythmias induced by sympathetic nerve stimulation.
Cardiac arrhythmias produced by electrical stimulation of the ventrolateral cardiac sympathetic nerve in dogs were not blocked by the combined administration of propranolol and practolol in amounts that completely blocked cardiac beta-adrenergic receptors. Blockade of cardiac alpha-adrenergic receptors, as well as cardiac cholinergic receptors, also had no influence on the arrhythmias. These results suggest that the adrenergic neuroeffector junction is fundamentally different from any hitherto described, differing perhaps in the neurotransmitter involved or in the nature of the receptor.
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology*; D001285:Atropine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004562:Electrocardiography; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects; D009469:Neuromuscular Junction / Q000503:physiopathology; D010646:Phentolamine / Q000494:pharmacology; D011217:Practolol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000187:drug effects; D011950:Receptors, Cholinergic / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D011941:Receptors, Adrenergic; D011950:Receptors, Cholinergic; D001285:Atropine; D011433:Propranolol; D011217:Practolol; D010646:Phentolamine