粉防己碱对缺血-再灌注损伤大鼠心肌细胞凋亡及Bcl-2/Bax蛋白表达的影响

目的探讨粉防己碱对缺血-再灌注损伤大鼠心肌细胞凋亡及Bcl-2/Bax蛋白表达的影响。方法结扎大鼠左冠状动脉前降支（LAD）30min后松开,再灌注24h建立心肌缺血-再灌注损伤模型。将48只雄性SD大鼠随机分为：假手术组（Sham组）,缺血-再灌注损伤组（IRI组）,粉防己碱预处理组（Tet组）。再灌注结束后检测血清肌酸激酶同工酶MB（CK-MB）和心肌梗死范围（IS/AAR,%）。应用原位末端标记法（TUNEL法）检测各组凋亡细胞,计算凋亡指数（AI）,应用免疫组化法检测心肌Bcl-2、Bax蛋白表达,计算Bcl-2/Bax值,进行组间比较。结果与IRI组相比,Tet可明显降低CK-MB值（976.57±160.69）vs（1910.38±221.10）U/L,P〈0.01,减小心肌IS/AAR%,（23.28±4.38）%vs（43.76±6.30）%,P〈0.01。与IRI组比较,粉防己碱预处理可显著减少心肌细胞凋亡,AI显著降低（8.62±2.45%vs19.36±5.28%,P〈0.01）。粉防己碱预处理使Bcl-2表达增加,Bax表达下降,Bcl-2/Bax值显著升高（P〈0.01）。结论粉防己碱能明显抑制缺血-再灌注损伤引起的心肌细胞凋亡,其作用机制可能与促进Bcl-2蛋白表达,减少Bax蛋白表达、升高Bcl-2/Bax比值有关。

The Effect of Tetrandrine on Cardiomyocyte Apoptosis and Expression of Bcl-2/Bax Protein After Ischemia and Reperfusion Injury in Rats

Objective To investigate the effect of tetrandrine on cardiomyocyte apoptosis and expression of Bcl-2/Bax protein after isehemia and repeffusion injury in rats. Methods The Sprague-Dawley rats underwent 30 min of left anterior descending（LAD） coronary occlusion and 24 hours reperfusion to make isehemia/repefusion injury（IRI） model in vivo. 48 male rats were randomly divided into 3 groups： Sham group, IRI group, tetrandrine pretreatment group（ Tet group）. Creatine kianse isoenzyme-MB（CK-MB） was measured in each group, and the infarction size（IS/AAR%） was measured in IRI and Tet groups. The apoptotic index（AI） by TUNEL staining was measured in each group. The protein expression of Bel-2 and Bax was studied by immunohistochemieal staining, and the ratios of Bcl-2 and Bax were calculated. Results Compared with IRI group, the activity of CK-MB in serum was markedly decreased in Tet group （976.57 ± 160.69） vs （ 1910.38 ± 221.10） U/L, P 〈 0.01], the value of IS/AAR% in Tet group was lower than IRI group（23.28 ± 4.38% vs 43.76 ± 6.30%, P 〈0.01）. AI was significantly decreased in Tet group compared with IRI group（8.62 ± 2.45% vs 19.36 ± 5.28%, P 〈 0.01）. Compared with IRI group, the expression of Bax protein was decreased significantly and bcl-2 protein was increased significantly in Tet group. The ratios of Bel-2/Bax in Tet group were significantly increased . Conclusion Tetrandrine can significantly inhibit eardiomyocyte apoptosis induced by ischemia/reperfusion injury in rats. The possible mechanism is to raise the ratio of Bcl-2/Bax proteins by increasing expression of bcl-2 protein and inhibiting expression of Bax protein.