线粒体融合素2在糖尿病大鼠心肌损伤中的变化

The changes of mitofusin 2 on myocardial injury in diabetic rats

目的:探讨线粒体融合素2(mitofusin 2,Mfn2)在糖尿病大鼠心肌损伤中的变化。方法:腹腔注射55mg/kg链脲佐菌素复制糖尿病大鼠模型,分为正常组、糖尿病4周组和糖尿病8周组。测定血流动力学指标、大鼠心系数;自动生化分析仪测定血浆肌酸激酶同工酶(creatine kinaseisozyme,CK-MB)水平。RT-PCR检测左室心尖部组织Mfn2的表达。结果:与正常大鼠相比,糖尿病4周、8周大鼠左室发展压、左室最大上升和下降速率、心率、左室做功均明显下降(P<0.05,P<0.01),心室舒张末压上升(P<0.01),心系数(HW/BW)明显增加(P<0.01),血浆CK-MB水平升高(P<0.05,P<0.01),Mfn2mRNA的表达降低(P<0.01);与糖尿病4周相比,糖尿病8周大鼠左室发展压、左室最大上升速率和下降速率、心率及左室做功进一步下降(P<0.05,P<0.01),心室舒张末压升高(P<0.01),HW/BW、CK-MB水平持续性升高(P<0.01),Mfn2mRNA的表达进一步降低(P<0.01)。结论:随着糖尿病病程的延长,糖尿病大鼠心室功能进一步下降,其机制可能与Mfn2的表达降低有关。

AIM： To investigate the changes of mitofusin 2（Mfn2） on myocardial injury in diabetic rats.METHODS： Diabetic rat model was simulated by intraperitoneal injection 55 mg/kg streptozotocin and divided into normal group,diabetes at 4th week（DM 4W）,and diabetes at 8th week（DM 8W） groups.The ventricular hemodynamical parameters in vitro and heart weight/body weight（HW/BW） were determined.The level of CK-MB in serum was determined by automatic biochemistry analyzer.Mfn2 mRNA expression of left anterior myocardium was evaluated by RT-PCR.RESULTS：In contrast to normal rat,left ventricular developed pressure（LVDP）,maximal rise/fall rate of left ventricular pressure（±dp/dtmax）,heart rate（HR）,left ventricular work（RPP） and CK-MB level were decreased in DM 4W and DM 8W rats（P0.05,P0.01）,left ventricular end diastolic pressure（LVEDP） and HW/BW were increased（P0.01）,and the expression of Mfn2 mRNA was decreased（P0.01）;compared with DM 4W rat,LVDP,±dp/dtmax,HR,RPP and CK-MB level were further decreased in DM 8W rat（P0.05,P0.01）,LVEDP and HW/BW were increased（P0.01）,and the expression of Mfn2 mRNA was further decreased（P0.01）.CONCLUSION： With the development of diabetes,ventricular function was decreased further,it is maybe related to the decrease of Mfn2 mRNA expression.