Role of β-Adrenoceptors and L-Type Ca(2+)-Channels in the Mechanism of Reperfusion-Induced Heart Injury.

We studied the effects of β-adrenoceptor antagonists propranolol and nadolol and L-type Ca(2+)-channel blocker verapamil on cardiac reperfusion injury developed after 45-min coronary occlusion. The substances were injected intravenously 5 min before reperfusion. The results indicate that activation of β-adrenoceptors and opening of L-type Ca(2+)-channels promote the development of cardiac reperfusion injury, while blockage of β-adrenoceptors and/or L-type Ca(2+)-channels prevents reoxygenation-induced myocardial injury. Propranolol, nadolol, and verapamil can produce infraction-limiting effects after onset of ischemic heart injury.