Anti-arrhythmic effects of U50,488H involving the inhibition of Na~+ current in ischemia/reperfusion rat heart / 中国药理学通报

ABSTRACT

Aim To investigate the effects of U50,488H(a selective ?-opioid receptor agonist)on ventricular arrhythmias induced by myocardial ischemia and reperfusion in rats and to elucidate their mechanisms.Methods The contents of CK(creatine phosphokinase)and LDH(lactate dehydrogenase)were measured; The isolated heart was perfused using langendorff equipment. Heart rate(HR), arterial blood pressure(ABP), left ventricular pressure (LVP), cardiac function (?dp/dtmax), rate of ventricular tachycardia(VT)and ventricular fibrillation(VF)were examined in rats in vitro. The incidence of ventricular arrhythmias and arrhythmia score were also determined; The change of sodium currents (INa) induced by U50,488H was detected by whole-cell recording mode using patch clamp.Results ① In comparison with I/R group, the contents of CK、LDH in plasma of rats in U50,488H+I/R group were significantly lowered(P