The protective effects of nicotinamide on experimental myocardial injury

AIM： To investigate the protective effects of nicotinamide (Nic) on experimental myocardial injury induced by adriamycin (ADR) in rats and its mechanisms. Methods： Wistar rats (n ＝60) were randomly divided into Normal， ADR， Nic Ⅰ ， Nic Ⅱ and Nic Ⅲ groups. The myocardial injury model was established by peritoneum injection of ADR several times. 5-week the left vcntricular function，the levels of SOD， GSH-PX and MDA in myocardium which were perfused in a Langendorff mode was measured later， and the changes of the ultrastructure of myocardium were observed by electron microscope. Results： In rats only received ADR， the left ventricular function and the activities of SOD and GSH-PX in myocardium were decreased， and the content of MDA was increasd， as well as the destruction of ultrastructure of myocardium emerged. Nic (100 mg， 200 mg， 300 mg/kg) could improve the left ventricular function which decreased by ADR， increase the activities of SOD and GSH-PX， decrease the content of MDA and prevent the destruction on ultrastructure of myocardium from ADR. Conclusion： Nic has the protective characters on experimental myocardial injury induced by ADR. The mechanism is probably related to inhibiting lipid peroxidation and improving systole and diastole of heart.