Preconditioning against myocardial dysfunction after ischemia and reperfusion by an α1-adrenergic mechanism

Abstract

Preconditioning may find ready applicability in humans facing scheduled global cardiac ischemia-reperfusion (IR) during bypass or transplantation, where such a maneuver is feasible before arrest. Our objective was to delineate and exploit the endogenous preconditioning mechanism triggered by transient ischemia (TI) and thereby attenuate myocardial postischemic mechanical dysfunction by clinically acceptable means. Preconditioning by 2 minutes of TI followed by 10 minutes of normal perfusion protected isolated rat left ventricle function assessed after 20 minutes of global, 37°C ischemia and 40 minutes of reperfusion. Final recovery of developed pressure (DP) was improved (91.5±1.9% of equilibration DP versus unconditioned IR control, 57.4±2.4%, P