Effects of a cardio-selective beta-adrenergic blocking agent on the heart and coronary circulation

Abstract

ICI 50,172, a new β-adrenergic blocking agent, prevented the inotropic effects of intra-coronary isoprenaline, adrenaline, and noradrenaline. Small doses of ICI 50,172 sufficient to block the myocardial response to isoprenaline failed to block its coronary vasodilator action. Similar doses of ICI 50,172, which prevented the myocardial response to adrenaline or noradrenaline, blocked or reversed the coronary dilator effect of these agents.