Protective Effect of Tea Polyphenol on Rat Myocardial Injury Induced by Isoproterenol / 中草药

ABSTRACT

Iretreatment with tea polyphenol (TP) at a dose of 10mg/kg ip to rats five days before isoproterenol (ISO) challenge (1mg/kg sc, for two days), resulted in decreases of malonydialdehyde concentration, creatine phosphokinase, lactic dehydrogenase (LDH) and LDH1,activities; increased LDH2/LDH1 ratio and inhibited the extent of myocardial injury, similar to the action of propranol. At the same time TP decreased rat plasma renin activity.The results suggested that the mechanism by which TP protects heart from ISO-induced myocardial injury is due to its antioxygen free radical and inhibition of renin activities.