Myocardial protective effects of nicorandil and verapamil during ischemia-reperfusion in an isolated perfused rat heart

ABSTRACT

BACKGROUND: To reduce or prevent myocardial injury during an ischemia-reperfusion episode, some pharmacological interventions, including administering nicorandil or verapamil, have becomepopular in clinical situations. Nicorandil is a N-(2-hydroxyethyl)- nicotinamide nitrate ester, and it's effective mainly by opening the K+ ATP channels in the mitochondrial membrane, and verapamil is useful for reducing the endothelial injury of coronary vessels during ischemia. In this study, we aimed to determine the cardioprotective effect when both drugs are used simultaneously. METHODS: Isolated rat hearts (the Langendorff perfusion model) were perfused with Krebs-Henseleit bicarbonate buffer. After 30 minutes of controlled perfusion, we added nicorandil or verapamil separately and both drugs were administered together in another group (the mixed group) and we then induced ischemia for 30 minutes. We measured the heart rate, the developed ventricularpressure and the dP/dT during the control period during drug infusion and during reperfusion at 15, 30, 45 and 60 minutes. RESULTS: During reperfusion, the mixed group showed more favorable results for the developed left ventricular pressure (LVP), the dP/dT and the rate pressure product (RPP). The heart rate was significantly decreased as reperfusion processed in all the groups. CONCLUSIONS: For myocardial protection during ischemia-reperfusion, a mixed drug regimen is more beneficial than a single drug regimen, and this occurs without inducing a significant decrease of the heart rate.