Prevention of sinomenine on isolated rat myocardial reperfusion injury

Acute myocardial ischemia and reperfusion injury of rats were produced by ligating the left coronary artery for 15 min and reopening. The myocardial calcium contents were increased from 3.53 +/- 0.58 mumol/g dry wt in sham operation group to 6.02 +/- 1.19 mumol/g dry wt with reducing SOD/MDA ratio and showing ventricular extrasystole (VE), ventricular tachycardia (VT), and ventricular fibrillation (VF). Sinomenine (Sin) and verapamil (Ver) infusion 15 min before ischemia attenuated the elevated calcium contents to the level of the sham operation group, increased SOD/MDA ratio, and produced antagonistic effects on VE, VT, VF. These improvements indicated that Sin, similar to Ver, prevented myocardial injury by lowering intracellular Ca2+ accumulation.