Relationship of severity of myocardial stunning to ATP dependent potassium channel modulation.

Pharmacological modulation of ATP sensitive potassium channels (K+ATP channels) in vivo may influence ischemia and reperfusion injury of myocardium. The purpose of this investigation was to ascertain the actions of multiple K+ATP channel openers and interactions with a K+ATP channel antagonist in a model of stunned myocardium in anesthetized and conscious dogs. The results indicate that the K+ATP channel openers, aprikalim and nicorandil, enhance recovery of regional contractile function of stunned myocardium. This action was blocked by the selective K+ATP antagonist, glyburide. The beneficial effects of K+ATP channel openers were not related to changes in systemic hemodynamics or coronary collateral perfusion, but instead may be a manifestation of direct cardioprotective actions of these compounds.