Vagal Modulation of Epicardial Coronary Artery Size in Dogs

Abstract

Vagus nerve activity maintains tonic dilation of the left circumflex coronary artery by muscarinic receptor activation. Each vagus nerve contributes approximately equally to the tonically dilated state. Vagotomy-induced vasoconstriction occurs independently of local metabolic factors and coronary distending pressure and is a result of cholinergic withdrawal rather than reflex sympathetic activation.