雌二醇对大鼠心肌缺血-再灌注损伤的影响

Effects of estrogen on myocardial ischemic-reperfusion injury in rats

目的探讨雌激素对大鼠在体心脏缺血-再灌注(I-R)后心功能及心肌凋亡的影响。方法健康雌性成年SD雌鼠50只,随机均分为5组:假手术组(C组),双侧卵巢切除组(A组)和双侧卵巢切除后补充低、中、高剂量17β-雌二醇组(AL组、AM组、AH组)。A组、AL组、AM组、AH组术后第4周末制作在体I-R模型,缺血30 min、再灌注120 min后观察心功能及心肌细胞凋亡情况。结果 A组大鼠体重迅速增加,子宫萎缩,血清雌激素水平下降。A组、AL组左心室舒张末压(LVDEP)、丙二醛(MDA)生成、肿瘤坏死因子(TNF-α)、肌钙蛋白(TnT)、心肌梗死面积增加,左心室收缩压(LVSP)、±dp/dtmax、超氧化物歧化酶(SOD)活性、B细胞淋巴瘤-白血病2/Bcl相关X蛋白(Bcl-2/Bax)降低;AM、AH组上述作用能被逆转(P<0.05)。结论中、高剂量雌激素能够通过提高抗氧自由基能力、抑制炎症因子、减小心肌梗死面积、减少心肌细胞凋亡,减轻大鼠在体心脏I-R损伤。

Objective：To explore the effects of estrogen on hemodynamics and cardiomyocytes apoptosis in rat hearts subjected to ischemic-reperfusion（I-R） injury.Methods：Fifty female SD rats were randomly divided into 5 groups with 10 rats each.Group C was sham operated.Ovariectomized rats were treated with placebo（group A） or three different doses of 17 β-estradiol replacement（group AL,AM and AH） for four weeks,followed by I-R in vivo（ischemia for 30 min and reperfusion for 120 min）.Hemodynamic parameters and cardiomyocytes apoptosis were measured at the end of ischemia and reperfusion.Results：Body weight was dramatically increased with metratrophia and reduction of serum estrogen in group A.In groups of A and AL,LVDEP,MDA and TNF-α production,TnT release and the area of myocardial infarct were all significantly increased,whereas LVSP,±dp/dtmax,SOD activity and ratio of Bcl-2/Bax were decreased,all of which were reversed in groups of AM and AH（P0.05）.Conclusion：Middle and high doses of estrogen can effectively protect myocardial I-R injury in vivo by elevating the capability of anti-oxygen free radical,inhibiting inflammation factor and reducing the area of myocardial infarct and myocardiocyte apoptosis.