给大鼠腹腔注射茶多酚（10mg/kg）5d后，皮下注射异丙肾上腺素（1mg/kg）连续2d。结果发现茶多酚和普萘洛尔均使大鼠血清丙二醛、磷酸肌酸激酶、乳酸脱氨酶（LDH）及LDH1较生理盐水组下降，LDH2/LDH1比值增加。同时，茶多酚使大鼠血浆肾素活性降低。HE染色亦显示病理损伤减轻。结果提示，茶多酚对异丙肾上腺素诱发大鼠的心肌损伤有保护作用，机理与其抗氧自由基和抑制肾素活性有关。

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.