急性高血糖对急性心肌梗死大鼠心肌细胞线粒体膜电位的影响

Effect of Acute hyperglycaemia on Mitochondria Membrance Potential after acute myocardial infarction in rats

目的研究急性心肌梗死后急性高血糖对大鼠心肌细胞线粒体超微结构和膜电位的影响。方法结扎40只雄性SD大鼠左冠状动脉前降支建立急性心肌梗死模型后随机分为4组:对照组、高糖1组、高糖2组和胰岛素组,另取10只SD大鼠设为假手术组,术中监测血糖水平,实验终点观察各组大鼠心肌细胞凋亡指数、线粒体和胞浆内细胞色素C表达以及线粒体超微结构和膜电位变化。结果与假手术组相比较,余各组细胞凋亡指数均增高,线粒体超微结构均不同程度损失变化,线粒体膜电位均降低;胞浆细胞色素C表达增加而线粒体内细胞色素C表达减少(P<0.05)。与高糖2组相比,其余各组细胞凋亡指数显著减低,线粒体超微结构损伤程度较轻,线粒体膜电位显著增高,细胞色素C胞浆表达显著减少而线粒体表达显著增加(P<0.05)。结论急性心肌梗死后急性高血糖可能通过损伤线粒体显著促进细胞凋亡,注射胰岛素降低血糖能有效地减少细胞凋亡。

Aim To study the effects of acute hyperglycaemia on Mitochondria Membrance Potential and Cytochrome c after AMI in rats without diabetes. Methods We ligated the left anterior descending coronary artery of fourty male SD rats to build the models of AMI.Then,These animals were randomly divided into 4 groups： CON group,HG1 group,HG2 group and insulin group;And another ten male SD rats were used as Sham group,Blood glucose levels were monitored throughout the experiment.Apoptotic index（AI）,Mitochondria Membrance Potential,mitochondria and endochylema Cyt-c were measured. Results Compared with SHAM group,the AI and endochylema Cyt-c were significantly higher in other groups;The Mitochondria Membrance Potential and the expression of mitochondria Cyt-c were significantly lower in other groups.The things were diametrically opposed in the HG2 group.The Mitochondria Membrance Potential and the expression of Cyt-c were not significantly different in CON group,HG1 group and insulin group. Conclusion Acute hyperglycaemia after AMI has significant influences on apoptosis in rats by way of Mitochondria,We can protect cardiac muscle cell by injecting insulin which can reduce blood glucose.