表没食子儿茶素没食子酸酯改善心肌缺血再灌注大鼠心功能作用的研究

目的 :研究表没食子儿茶素没食子酸酯 ( EGCG)对心肌缺血再灌注损伤大鼠心功能的改善作用。方法 :采用结扎大鼠左冠状动脉前降支 30 min后松开再灌注 60 min的方法建立在大鼠缺血再灌注模型。实验分假手术组、缺血再灌注组 ( I/R)、EGCG( 1 0 mg/kg)与 EGCG( 2 0 mg/kg)治疗组、丹参对照治疗组。用心功能分析系统全程记录缺血再灌注期间心功能的变化。实验结束后 ,取血测定血浆超氧化物歧化酶 ( SOD)、脂质过氧化产物丙二醛( MDA)、乳酸脱氢酶 ( L DH)、肌酸激酶 ( CK)、一氧化氮 ( NO)和肿瘤坏死因子 - α( TNF- α)水平 ;取左室心肌用 4%多聚甲醛固定切片 ,用 TUNEL法检测心肌细胞凋亡并计算凋亡指数( AI)。结果 :I/R组在缺血及再灌注期间 ,大鼠左室功能呈进行性下降 ,血浆 SOD与 NO水平显著降低 ,同时 MDA、LDH、CK及 TNF- α水平显著升高 ,心肌细胞 AI明显增加 (与假手术组比 ,P<0 .0 1 )。EGCG及丹参治疗组大鼠心功能明显改善 ,血浆 SOD与 NO明显升高 ,MDA、L DH、CK及 TNF- α水平则显著降低 ,同时 AI亦明显降低 (与 I/R组比 ,P<0 .0 1 )。结论 :EGCG通过抗脂质过氧化作用保护心肌和内皮细胞 ,促进 NO合成 ,抑制 TNF- α的表达及细胞凋亡 ,对缺血再灌注损伤引起的大鼠心功能降低有明显改善作用。

Study of epigallocatechin gallate in improving cardiac function in rats with myocardial ischemia reperfusion

Objective:To study the effects of epigallocatechin gallate(EGCG) on the left cardiac function during myocardial ischemia reperfusion(MIR) in rats. Methods:The MIR model was establshed by left descending anterior coronary artery (LAD)ligation for 30min, followed by 60min of reperfusion. The experiment was divided into five groups: sham, ischemia/ reperfusion(I/R), EGCG(10mg/kg and 20mg/kg) and salvia miltiorrhizae (SM,100mg/kg) group. The left cardiac function was measured by the analysis system; the levels of SOD,MDA,LDH,CK,NO and TNF-α in plasma and the cell apoptotic index (AI) were measured. Results:Compaerd with sham group, in I/R group the left cardiac function and the level of SOD and NO in plasma were decreased, while the MDA,LDH,CK,TNF-α and AI were increased (P<0.01). Compared with I/R group, in EGCG or SM group the left cardiac function was improved significantly, the level of SOD and NO were increased obviously while the MDA,LDH,CK,TNF-α and AI were decreased markedly (P<0.01). Conclusion:EGCG can improve left cardiac function of rats with MIR. The mechanism may be related to its inhibiting myocardial lipid peroxidation , enhancing the level of NO , inhibiting the expression of TNF-α and cell apoptotic in myocardial.