环孢素A对缺血-再灌注大鼠心肌细胞凋亡的影响

Effects of cyclosporin A on cardiomyocyte apoptosis after ischemia-reperfusion in rats

目的通过观察环孢素A(CsA)对大鼠心肌缺血-再灌注损伤细胞凋亡相关蛋白的影响,探讨缺血-再灌注时心肌细胞凋亡的线粒体机制。方法使用结扎/松解冠状动脉左前分支缺血30min,再灌注3h复制缺血-再灌注模型。SD大鼠随机分为三组:假手术组(S组),缺血-再灌注组(IR组),CsA预处理组(CsA-IR组),每组6只。CsA预处理为缺血前经静脉注射CsA10mg/kg,S组与IR组则分别在缺血前经静脉注射同等容积的生理盐水。TUNEL法原位标记凋亡心肌细胞,荧光分析法检测Caspase-3活性。另取12只大鼠,按TTC染色法测定心肌梗死范围。结果与S组相比,IR组心肌细胞凋亡指数(AI)和Caspase-3活性均明显增高(P<0·01)。与IR组相比,CsA-IR组的AI、Caspase-3活性及心肌梗死范围均显著减少(P<0·05或P<0·01);但其AI和Caspase-3活性均明显高于S组(P<0·05或P<0·01)。结论CsA对大鼠心肌缺血-再灌注损伤具有保护作用。该作用可能与阻断心肌细胞线粒体膜通透性转换孔(PTP)、降低Caspase-3活性而抑制凋亡的发生有关。PTP开放可能是缺血-再灌注时心肌细胞凋亡的重要环节。

Objective To investigate the effects of cyclosporin A（CsA） on cardiomyocyte apoptosis after ischemia-reperfusion. Methods Adult male SD rats were divided randomly into three groups with 6 rats each： sham operation group, ischemia-reperfusion （IR） group and CsA-IR group. The rats in CsA-IR group were given intravenously 10 mg/kg CsA before ischemia while those in the other 2 groups were given normal saline of the same volume. The apoptotic cells were assessed by TUNEL staining and apoptosis index（AI） was obtained. The activity of Caspase-3 was determined by fluorescent assay, and the myocardial infarction area was evaluated by TTC dyeing. Results Compared with those in sham group, AI and Caspase-3 activity increased significantly in IR group and CsA-IR group（P〈0.01）. The AI, Caspase-3 activity and myocardial infarct size in CsA-IR group were significantly lower than those in IR group （P〈0.05 or P〈0.01 ）. Conclusion CsA can prevent cardiomyocyte apoptosis after ischemia-reperfusion through blockade of permeability transtion pore （PTP） and inhibiting the activity of Caspase-3. Mitochondrial PTP might play an important role in cardiomyocyte apoptosis induced by ischemia-reperfusion injury.