二氢槲皮素预处理对心肌缺血/再灌注损伤抗氧化作用的影响

摘要

目的 探讨二氢槲皮素(dihydroquercetin,DDQ)对大鼠离体心脏缺血/再灌注损伤抗氧化作用的影响.方法 SD大鼠40只,随机分为正常组、模型组、二氢槲皮素低剂量组(5 mg·L-1)、二氢槲皮素高剂量组(10 mg·L-1)4组.使用Langendorff 逆行恒压灌流方式建立离体大鼠心脏I/ R模型.观察I/R期间DDQ对左心室舒张压、左心室收缩压、室内压最大上升速率、室内压最大下降速率和心率的影响.乳酸脱氢酶(LDH)水平和血清肌酸激酶(CK)的含量均采用酶联免疫吸附法进行分析,TTC染色法评价心肌梗死程度,测定心肌组织中超氧化物歧化酶(SOD)、还原型谷胱甘肽/氧化型谷胱甘肽(GSH/GSSG)和丙二醛(MDA)含量,HE染色观察心肌组织学结构的病变.结果 与模型组比,DDQ预处理组能够明显改善血流动力学的各项指标;DDQ预处理组可使心肌组织中的SOD和GSH/GSSG的含量明显增加;CK,LDH和 MDA 的含量明显降低,同时降低心肌梗死程度,减轻心肌组织学病变.结论 DDQ对离体大鼠缺血/再灌注损伤具有明显的保护作用,此保护作用可能与DDQ提高氧自由基清除能力,减少氧自由基产生,降低脂质过氧化损伤的作用机制有关.%Aim To investigate the protective effects of dihydroquercetin(DDQ) against myocardial ischemis reperfusion injury(MIRI) in rats.Methods Male Sprague-Dawley rats were randomly divided into 4 groups(n=10):normal,control,I/R model, and I/R model+DDQ(5,10 mg·L-1).This study used an isolated Langendorff rat heart model.The left ventricu-lar developed pressure(LVDP),heart rate(HR) and the maximum rise and fall rate of the left ventricular pressure(±dp/dtmax) were monitored and documented using a physiological recorder.The levels of lactate dehydrogenase(LDH) and creatine kinase(CK) were analyzed using enzyme-linked immunosorbent assay(ELISA).Infarct size was measured using 2,3,5-triphenyltetrazolium chloride staining.The levels of superoxide dismutase(SOD) and malondialdehyde(MDA), as well as the ratio of glutathione/glutathione disulfide(GSH/GSSG) were measured via ELISA.HE staining was used to observe the pathological changes of myocardial tissue.Results Compared with the I/R model group, the I/R model+DDQ groups raised hemodynamic parameters, SOD level, and GSH/GSSG ratio;and reduced the amount of CK, LDH, MDA levels.Moreover, the I/R model+DDQ groups had lower infarct size and pathological changes in myocardial tissue than I/R model group.Conclusion DDQ exertes cardioprotective effects against I/R via improving the oxygen free radical scavenging ability, the inhibition of oxygen free radical and reducing lipid peroxidation.