KKAy糖尿病鼠心肌损伤及葛根素的干预作用

目的：观察糖尿病心肌损伤出现的时间，分析其发生机制，探讨葛根素注射液的干预作用。方法: 全自动生化法检测17周、20周、24周和28周龄KKAy糖尿病模型鼠血清生化指标；流式细胞术检测小鼠心肌细胞凋亡百分率；RT-PCR 法检测小鼠心肌细胞bax、bcl-2 mRNA表达；免疫组化法检测小鼠心肌细胞caspase-3蛋白表达。结果: 与正常对照小鼠相比，除血糖增高外，20周、24周和28周龄KKAy糖尿病模型鼠血清中甘油三酯（TG）、胆固醇（TC）、低密度脂蛋白（LDL-C）、高密度脂蛋白（HDL-C）含量明显升高（P<0.01）。从28周起KKAy模型鼠心肌细胞开始凋亡；bax mRNA表达升高，bcl-2 mRNA表达降低；caspase-3蛋白表达升高。葛根素能减少心肌细胞的凋亡率，降低bax mRNA的表达水平，提高bcl-2 mRNA表达水平（P<0.01）,抑制心肌细胞caspase-3蛋白的表达（P<0.01）。结论: KKAy糖尿病模型鼠第28周存在心肌损伤；细胞凋亡的线粒体途径可能参与了损伤过程；葛根素可抑制KKAy糖尿病鼠心肌细胞凋亡。

Effect of puerarin on myocardial injury in KKAy diabetic mice

AIM:To observe the effect of puerarin on myocardial injury according to the time of occurrence of myocardial injury in the development of type 2 diabetic mice. METHODS: The serum levels of glucose (GLU), triglyceride (TG), total cholesterin (TC), low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C) in 17-week, 20-week, 24-week, 28-week KKAy mice were detected by automatic biochemical methods. The apoptotic percentage of cardiomyocytes was examined by flow cytometry. The expressions of bax and bcl-2 mRNA in cardiomyocytes were detected by RT-PCR. Caspase-3 expression in cardiomyocytes was determined by immunohistochemical staining. RESULTS: Compared to normal control mice, not only GLU level increased, but also the levels of TG, TC, LDL-C, HDL-C in 20-week, 24-week and 28-week KKAy mice increased apparently (P<0.01). Apoptosis of cardiomyocytes in KKAy mice began to show up at 28-week. The expression of bax mRNA increased and expression of bcl-2 mRNA reduced. At the same time, the expression of caspase-3 increased. Puerarin obviously decreased the apoptotic percentage of cardiomyocytes, reduced the expression level of bax mRNA, improved the expression level of bcl-2 mRNA (P<0.01), inhibited the expression of caspase-3 (P<0.01). CONCLUSION:Myocardial injury exits in type 2 diabetic mice. Mitochondria apoptotic pathway might participate in the hurting course.