Effects of mibefradil and verapamil on ischemic-reperfusion in the hearts of guinea pigs with acute renal failure

Abstract

Two parameters indicating the ischemic-reperfusion myocardial injury, coronary flow and lactate dehydrogenase (LDH) release rate, were evaluated in guinea pigs with gentamicine-induced acute renal failure (ARF) and compared with those of healthy animals. Isolated Langendorff’s hearts were exposed to 50 min of zero-flow global ischemia and 60 min of reperfusion. The influences of calcium channel antagonists (of T- and L-type antagonist mibefradil and of L-type antagonist verapamil) in reperfusion solution were evaluated. Our results showed coronary dilatation and higher LDH release rate in ARF than in control hearts before ischemia. Recovery of coronary flow during reperfusion was better and LDH release rate lower in ARF vs. control hearts. Perfusion with mibefradil and verapamil did not additionally increase coronary flow, however 0.1 μM mibefradil and verapamil decreased LDH release rate during reperfusion in ARF hearts in comparison to control hearts. Our results showed some protective effects of 0.1 μM mibefradil and verapamil on LDH release rate during reperfusion, but not on coronary flow in guinea pigs hearts with ARF.