普罗布考对心肌梗死大鼠心肌组织Bcl-2和Bax表达及氧化应激的影响
Effects of Probucol on Expression of Bcl-2,Bax and Oxidative Stress in Myocardial Infarcted Rats
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摘要: 背景心肌梗死后心肌细胞凋亡与氧化应激有关,普罗布考为脂溶性强抗氧化剂,实验证明具有保护心肌细胞的作用,该药保护心肌细胞的作用是否通过调控细胞凋亡相关基因 Bcl-2和 Bax 目前尚不清楚。目的研究普罗布考对心肌梗死大鼠心肌组织 Bcb-2和 Bax 表达及氧化应激的影响。方法将心肌梗死后24 h 存活大鼠41只随机分为2组:盐水组(5 mL/d,n=20),普罗布考组60 mg/(kg·d),n=21,灌胃给药;另设假手术组(n=12)作对照。分别于心肌梗死后6周:导管法测定左室有创血流动力学指标,TUNEL 法检测非梗死区心肌细胞凋亡;RT-PCR 的方法观察心肌组织 Bcl-2及 Bax mRNA 表达的变化;Western blot 检测心肌 Bcl-2及 Bax 蛋白表达;比色法测定心肌组织氧化代谢指标。结果 (1)与假手术组相比,所有心肌梗死大鼠均出现显著的 Bcl-2 mRNA 及蛋白表达降低,Bax mRNA 及蛋白表达与心肌细胞凋亡指数显著升高(P 均<0.01)。与盐水组相比,普罗布考组心肌组织 Bcl-2 mRNA 及蛋白表达显著升高,Bax mRNA 及蛋白表达及心肌细胞凋亡指数显著降低(P 均<0.01);(2)与假手术组相比,所有心肌梗死大鼠心肌组织均出现显著的 MDA 升高,SOD、TAOC 含量及 SOD/MDA 比值降低(P 均<0.01);与盐水组相比,普罗布考组 MDA 显著下降,SOD、TAOC 含量及 SOD/MDA 均升高(P 均<0.01);心肌细胞凋亡指数与 TAOC、SOD/MDA 比值呈负相关(P 均<0.01)。结论心肌梗死后心肌细胞凋亡增加,普罗布考治疗可以抑制心肌细胞凋亡,降低心肌梗死后心肌组织的氧化应激。Abstract: Background Cardiomyocytes apoptosis was related to oxidative stress which has been shown to play an important role in ventricular remodeling after myocardial infarction（MI）.Probucol is a hypolipidemic and antioxidant agents.Several reports demonstrated its cardioprotective effect after MI.However,the exact effect of probucol on the modification of the apoptosis related gene Bcl-2 and Bax is not clear.Objective To investigate the effects of probucol on mRNA and protein expression of Bcl-2,Bax and oxidative stress in myocardial infarcted rats.Methods Forty-one SD rats that survived 24 h after ligating left anterior descending coronary artery were randomly to receive placebo-saline（5 mL/d,n=20）or probucol（probucol 60 mg/kg·d,n=21）.Twelve rats underwent sham operation were served as control（n=12）.Six weeks after treatment,hemodynamic pararmeters and left ventricular function were measured with catheterization.Cardiomyocytes apoptosis were determined by TUNEL method.Myocardium mRNA of Bcl-2 and Bax expression levels in the non-infarcted myocardium were as- sessed by RT-PCR.The myocardium protein expression of Bcl-2 and Bax in the non-infarcted myocardium were de- termined by Western blot.Colorimetry was used to determine oxidative metabolism index in myocardium.Results 1)Compared with the sham rats,all MI rats showed marked decrease in Bcl-2 mRNA and protein expression in myo- cardium with increase of Bax mRNA and protein expression and apoptosis index（P＜0.01,respectively）.Com- pared with placebo rats,probucol increased Bcl-2 mRNA and protein expression,decreased Bax mRNA and protein expression and apoptosis index（P＜0.01,respectively）.2)Compared with the sham rats,all MI rats showed marked increase in MDA,and decrease in SOD,TAOC and SOD/MDA ratio（P＜0.01,respectively）.Probueol decreased MDA with concomitantly increased SOD,TAOC and SOD/MDA ratio（P＜0.01,respectively）.Myocar- dium apoptosis index was negatively correlated with TAOC and SOD/MDA ratio（P＜0.01,respectively）. Conclusion Cardiomyocytes apoptosis was increased after myocardial infarction.Probueol inhibit cardiomyocytes apolptosis and reduce oxidative stress.
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