原花青素对缺血再灌注大鼠心肌细胞凋亡及凋亡相关基因蛋白表达的影响

Effects of Procyanidin on Myocardial Apoptosis and Related Protein Expressions in Experimental Rats With Myocardial Ischemia Reperfusion Injury

目的:观察原花青素对缺血再灌注大鼠心肌细胞凋亡相关基因半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)、B型白细胞/2型淋巴细胞样蛋白(Bcl-2)和凋亡相关基因Bcl-2相关X蛋白(Bax)蛋白表达的影响,探讨原花青素在大鼠缺血再灌注心肌细胞凋亡中发挥的作用及可能的调控机制。方法:40只雄性SD大鼠随机等分为4组,即正常组,模型组,原花青素低剂量组[原花青素50 mg/(kg·d)],原花青素高剂量组[原花青素100 mg/(kg·d)],灌胃给药,每天1次,连续2周。末次给药后结扎冠状动脉左前降支(LAD)30 min再灌注120 min,建立大鼠心肌缺血再灌注模型。测定肌酸激酶同工酶(CK-MB)活性、心肌梗死面积;用Western blot检测各组细胞凋亡相关基因Caspase-3、Bcl-2、Bax蛋白表达;原位末端转移酶标记(TUNEL)法检测心肌细胞凋亡。结果:与正常组比较,模型组大鼠CK-MB活性显著增强、心肌梗死面积增大,心肌细胞凋亡指数升高,Caspase-3、Bax蛋白表达增强,Bcl-2蛋白表达、Bcl-2/Bax降低(P<0.05);与模型组比较,原花青素高、低剂量组大鼠CK-MB活性显著减弱、心肌梗死面积减小,细胞凋亡指数显著降低,Caspase-3、Bax蛋白表达显著减弱,Bcl-2蛋白表达、Bcl-2/Bax增加(P<0.05)。结论:原花青素可拮抗缺血再灌注大鼠心肌细胞凋亡,其机制可能与Caspase-3、Bax蛋白表达降低,Bcl-2表达升高,Bcl-2/Bax比例增加有关。

Objective： To observe the effects of procyanidins on myocardial apoptosis and related protein expressions of caspase-3, Bcl-2 and Bax in experimental rats with ischemia reperfusion（I/R） injury and to explore the possible mechanism. Methods： A total of 40 male SD rats were randomly assigned to 4 groups： Sham group, IR group, Low-dose procyanidin（50 mg·kg-1） group, and High-dose procyanidin（100 mg·kg-1） group. n=10 in each group and the rats were pre-treated by intra gastric drug administration once/day for 2 weeks, then left anterior descending artery（LAD） occlusion was conducted for 30 minutes followed by reperfusion for 120 minutes to establish IR model. Blood levels of CK-MB activity and myocardial infarction（MI） size were examined; protein expressions of caspase-3, Bcl-2 and Bax were determined by Western blot analysis; myocardial apoptotic index was measured by TUNEL method.Results： Compared with Sham group, IR group presented the higher CK-MB activity, enlarged MI size, increased index of apoptosis, elevated protein expressions of caspase-3 and Bax, while reduced protein expression of Bcl-2 and the ratio of Bcl-2/Bax, P〈0.05. Compared with IR group, both Low-dose and High-dose procyanidin groups had the lower CK-MB activity, smaller MI size,decreased index of apoptosis, reduced protein expressions of caspase-3 and Bax, while elevated protein expression of Bcl-2 and the ratio of Bcl-2/Bax, P〈0.05. Conclusion： Procyanidin could reduce myocardial apoptosis index in experimental IR rats, which might be related to decreased protein expressions of caspase-3 and Bax, increased protein expression of Bcl-2 and the ratio of Bcl-2/Bax.