曲美他嗪干预对心力衰竭大鼠心肌细胞线粒体超微结构、心肌细胞凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白、细胞色素C蛋白表达的影响

Effect of Trimetazidine on Myocardial Ultra-structure, Cardiomyocyte Apoptosis and Expressions of Caspase-3, Cytochrome C in Experimental Rats With Heart Failure

目的:探讨曲美他嗪干预对心力衰竭(心衰)大鼠左心室心肌细胞线粒体超微结构、心肌细胞凋亡及半胱氨酸天冬氨酸蛋白酶3(caspase-3)蛋白和细胞色素C蛋白表达的影响。方法:雄性wistar大鼠30只随机分为假手术组、心衰模型组、曲美他嗪组,每组10只。除假手术组外,其余两组大鼠采用肾上腹主动脉缩窄法建立慢性心衰模型,其中曲美他嗪组大鼠给予曲美他嗪10 mg/(kg·d)灌胃4 w。观察各组左心室舒张末期压(LVEDP)、左心室压力最大上升及下降速率(±dp/dtmax);苏木素伊红(HE)染色法观察大鼠心肌细胞形态结构;透射电镜观察心肌细胞线粒体超微结构;原位缺口末端标记(TUNEL)法检测心肌细胞凋亡指数(AI);SP免疫组织化学法检测各组大鼠左心室心肌细胞caspase-3蛋白、细胞色素C蛋白的表达。结果:与假手术组比较,心衰模型组大鼠心肌细胞线粒体形态发生明显改变,排列紊乱,空泡变性,LVEDP显著升高(P<0.01),±dp/dtmax明显降低(P<0.01),心肌细胞凋亡指数、caspase-3蛋白及细胞色素C蛋白的表达水平升高,差异均有统计学意义(P<0.01);与心衰模型组相比,曲美他嗪组大鼠心肌细胞线粒体形态变化明显改善,LVEDP明显下降(P<0.01),±dp/dtmax显著升高(P<0.01),心肌细胞凋亡指数、caspase-3蛋白及细胞色素C蛋白的表达水平降低,差异均有统计学意义(P<0.01)。结论:曲美他嗪可有效改善心功能,抑制心肌细胞凋亡,其机制可能与保护心肌细胞线粒体功能有关。

Objective： To investigate the effect of trimetazidine on myocardial ultra-structure, cardiomyocyte apoptosis, and expressions of caspase-3, cytochrome C in experimental rats with heart failure （HF）. Methods： A total of 30 male Wister rats were randomly divided into 3 groups： Sham group, the rats received operation without constriction, followed by intragastric administration of normal saline, n=10; the rest animals received suprarenal aortic constriction to establish HF model and further divided into 2 group： HF model group, the rats received intragastric administration of normal saline and Trimetazidine group, the rats received intragastric administration of timetazidine at 10 mg/（kg·d）, n=10 in each group, all animal were treated for 4 weeks. Left ventricular end diastolic pressure （LVEDP） and the maximum left ventricular pressure rising and falling （±dp/dtmax） were measured. The morphology of myocardium was observed by HE staining, myocardial ultra-structure was examined by transmission electronic microscopy, apoptotic index （AI） was detected by TUNEL assay. The expressions of caspase-3 and cytochrome C were evaluated by immunohistochemistry. Results： Compared with Sham group, the rats in HF model group showed the morphological changes of myocardial mitochondria as disordered structure with vacuolar degeneration; increased LVEDP, P〈0.01 and decreased （±dp/dtmax）, P〈0.01; elevated AI and the expressions of Caspase-3, Cytochrome C, P〈0.01. Compared with HF model group, the rats in Trimetazidine group presented obviously improved myocardial mitochondrial morphology, much lower LVEDP, P〈0.01 and higher （±dp/dtmax）, P〈0.01; reduced AI and the expressions of Caspase-3, Cytochrome C, P〈0.01. Conclusion： Trimetazidine may effectively improve cardiac function and inhibit cadiomyocyte apoptosis, which might be related to the protection of mitochondrial function in experimental HF rats.