Nicorandil protects ATP-sensitive potassium channels against oxidation-induced dysfunction in cardiomyocytes of aging rats

ATP-sensitive potassium channels (KATP channels) regulate vascular tone and cardiac contraction through their action on the membrane potential of smooth muscle cells and cardiomyocytes. Because aging and diseases alter KATP channel activity, many pharmacological treatments aimed at improving their function, therefore cardiovascular function, have been evaluated. Nicorandil, a KATP channel opener, nitric oxide donor and antioxidant, is used as a treatment of angina pectoris and induces vasodilation, blood pressure decrease and cardioprotection in aging as well as after ischemia-reperfusion. Here, using the patch-clamp technique, we have studied the effect a chronic low dose of nicorandil (0.1 mg/kg per day for 2 months), on the activity of cardiomyocyte KATP channels as a function of age, in newborn, 4-, 12- and 24-month old rats. Nicorandil exerted an anti-oxidant and protective action on cardiomyocyte KATP channels, especially in aged animals, leading to restoration of a normal channel activity. These findings could justify further therapeutical applications.