表没食子儿茶素没食子酸酯对缺血再灌注损伤大鼠心肌脂质过氧化及心肌酶活性的影响

目的：观察表没食子儿茶表没食子酸酯（EGCG）对缺血再灌注损伤大鼠心肌脂质过氧化及心肌酶活性的影响。方法：雄性Wistar大鼠50只分为5组，假手术组、缺血再灌注组（IR），丹参（SM，100mg/kg）组，EGCG1（10mg/kg)组和EGCG2（20mg/kg）组，每组10只动物，采用结扎大鼠左冠状动脉前降支30min后再灌注60min的方法建立在体缺血再灌注损伤模型，分别测定心肌丙二醛（MDA）含量，超氧化物歧化酶（SOD）及ATP酶活性和血浆乳酸脱氢酶（LDH）水平。结果：与假手术组比，IR组大鼠心肌MDA及血浆LDH明显升高，SOD及ATP酶活性则显著降低（P＜0．01）；EGCG和SM均能显著，降低MDA与LDH，明显增加SOD与ATP酶活性（与IR组比，P＜0．01），并且EGCG（20mg/kg)，降低MDA与LDH的作用较SM（100mg/kg)更明显（P＜0．05）。结论：EGCG通过抑制脂过氧化反应和提高心肌SOD与ATP酶活性，对大鼠缺血再灌注损伤心肌有显著的保护作用。

Effects of Epigallocatechin Gallate on Lipid Peroxidation and Enzyme Activity in the Ischemia-Reperfusion Myocardium of Rats

Object To observe the effects of epigallocatechin gallate(EGCG) on lipid peroxidation and enzyme activity in the ischemia reperfusion myocardium of rats.Methods The experimental model was established by the 30min ligating and 60min reperfusing the left descending coronary artery(LAD) in rats.50 male wistar rats were averagely divided into five groups:sham,ischemia reperfusion (IR),Saliva Miltiorrhizae (SM,100mg/kg),EGCG1 (10mg/kg) and EGCG2(20mg/kg).The content of myocardial malondialdehyde (MDA),the activities of myocardial superoxide dismutase(SOD) and adenosinetriphosphatase (ATPase) and the level of plasma lactate dehydrogenase (LDH) were measured.Results Compared with sham group,in IR group the content of myocardial MDA and the level of plasma LDH were significantly increased (P<0.01),and the activities of myocardial SOD and ATPase were obviously decreased (P<0.01). EGCG and SM markedly reduced the myocardial MDA content and plasma LDH level,and obviously enhanced the activities of myocardial SOD and ATPase(P<0.01,compared with IR group).The effects of EGCG (20mg/kg) on MDA and LDH were stronger than that of SM(100mg/kg)(P<0.05).Conclusion EGCG can protect myocardium against ischemia reperfusion injury,its mechanism may be related to the inhibition of myocardial lipid peroxidation and the enhancement of myocardial SOD and ATPase activities.