牛膝多肽通过抑制氧化应激减轻大鼠心肌缺血/再灌注损伤

Achyranthes bidentata polypeptides reduce oxidative stress and exert protective effects against myocardial ischemic / reperfusion injury in rats

目的探讨牛膝多肽(ABPP)预处理对心肌缺血/再灌注(MI/R)损伤的影响及其机制。方法建立大鼠MI/R模型,将成年SD大鼠随机分为Sham(假手术)组、MI/R组、药物预处理(ABPP+MI/R)组。检测血流动力学、用氯化三苯基四氮唑和伊文思蓝双染法检测心肌梗死(MI)面积、以血浆肌酸激酶(CK)和乳酸脱氢酶(LDH)活性检测心肌损伤情况、以超氧化物、丙二醛(MAD)和超氧化物歧化酶(SOD)含量检测心肌氧化应激以及Western blot方法测定心肌组织中gp91^(phox)的表达。用TUNEL法检测心肌细胞的凋亡指数(AI),荧光分析法检测caspase 3活性。结果与MI/R组比较,ABPP预处理使左心室上升、下降最大速率(±LVd P/dtmax)升高(P<0.05),MI面积显著减少〔MI/R组为(36.0±3.0)%,ABPP组为(26.5±3.5)%,P<0.05〕,血浆CK和LDH水平分别降低到(1251±72)U/L和(1961±122)U/L(P<0.05),TUNEL阳性染色显著降低(P<0.05),caspase-3的活性增加(P<0.05),超氧化物蓄积减少(P<0.05),显着降低了gp91phox的表达(P<0.05),MDA的含量显著减少(P<0.05),SOD活性增加(P<0.05)。结论 ABPP降低氧化应激和对MI/R损伤的心肌具有保护作用。

AIM To investigate the effects of achyranthes bidentata polypeptides （ABPP） preconditioning on myocardial ischemia/reperfusion （MI/R） injury and to explore the possible mechanism. METHODS Male Sprague Dawley （SD） rats were randomly divided into three groups： sham, myocardial ischemia reperfusion （MI/R） and ABPP ＋ MI/R. Tne model of myocardial I/R injury in vivo was made by ligating the left anterior descending artery for 30 rain followed by 4 h of reperfusion in SD rats. Hemodynamics were measured and myocardial infarct size was measured by Evans blue and 2,3,5-triphenyhetrazolium chloride （Trc） stai- ning. The level of hyperoxide superoxide, malondialdehyde （MDA） and plasma creatine kinase （CK） were measured and the activities of antioxidant enzyme superoxide dismutase （SOD） and lactate dehydro- genase （LDH） were detected. The gp91ph was determined by Western blot, cardiomyocyte apoptosis was detected using in situ TDT-mediated dUTP nick end labeling （TUNEL） , activity of caspase-3 was determined by fluorescent assay and gp91 was determined by Western blot. RESULTS Compared withthose in the I/R group, left ventricular ± dp/dtmax in ABPP preconditioned rats increased significantly （ P 〈 0. 05）. The percentage of area of necrosis was reduced [ （ 36. 0 ± 3.0） % vs. （26. 5± 3.5 ） %, P 〈0. 05]. Plasma CK and LDH levels decreased, respectively, to （ 1251 ±72） U/L and （ 1961 ±122） U/L （P 〈0. 05 vs. MI/R）. ABPP preconditioning decreased superoxide accumulation （P 〈0. 05 vs. MI/R） and decreased gp91 phox expression （P 〈 0. 05 ）. Compared with those in the MI/R group, apoptosis index and expressions of caspase-3 were significantly attenuated in ABPP preconditioned animals （ P 〈 0. 05 ）. ABPP preconditioning markedly decreased gp91ph expression （ P 〈 0. 05 ）. CONCLUSION ABPP reduces oxidative stress and exerts eardioprotection against MI/R injury in rats.