不同强度的耐力运动对糖尿病大鼠骨骼肌GLUT4 mRNA表达的影响

Effects of endurance training with different intensities on GLUT4 gene expression in skeletal muscle of diabetic rats

目的:探讨不同强度的耐力运动对糖尿病大鼠骨骼肌GLUT4 mRNA表达的影响。方法:雄性SD大鼠,其中36只大鼠经尾静脉注射链脲霉素,建立糖尿病模型。然后随机分为低强度运动组(EL)、高强度运动组(EH)、低强度运动加胰岛素治疗组(LI)、高强度运动加胰岛素治疗组(HI)、胰岛素治疗非运动组(DI)和非胰岛素治疗非运动组(DM)。6只SD大鼠为非运动正常血糖组(CN)。耐力训练采用活动平板,胰岛素采用皮下注射,共8周。运用RT-PCR法测定骨骼肌GLUT4 mRNA。结果:DM组骨骼肌GLUT4 mRNA表达水平显著低于其它各组(P<0.05)。LI组骨骼肌GLUT4 mRNA表达水平明显增高接近CN组,并且显著高于DI组。DI组GLUT4 mRNA含量与EL、EH、HI各组相当,差异无显著性意义。结论:运动可以促进GLUT4m RNA的表达,而运动强度对GLUT4 mRNA表达量无显著影响;低强度运动加胰岛素所具有最佳的GLUT4 mRNA表达水平是其它单独干预措施所无法替代的。

Objective: To explore the effects of endurance training with different intensities on GLUT4 gene expression in skeletal muscle of diabetic rats.Method:Male Sprague-Dawley rats were used in this experiment. Thirty-six rats were subjected to establish diabetic model by injection of streptozotocin. The diabetic rats were divided randomly into six groups: low-intensity training (EL, n=6), high-intensity training (EH, n=6), low-intensity training with insulin injection(LI,n=6), high-intensity training with insulin injection (HI, n=6), control without insulin injection and training(DM,n=6) and control with insulin injection and no training (DI, n=6). Six non-diabetic rats were used as a normal control group without training(CN,n=6). Animals with endurance training were forced to running on motorized treadmill for 8 weeks. The insulin were subcutaneously injected for 8 weeks. Expressions of GLUT4 gene in skeletal muscle were measured by RT-PCR. Result: The expressions of muscle GLUT4 mRNA in DM group were significantly lower than that in other groups. The expressions of GLUT4 mRNA in LI group increased to the level of CN group and were significantly higher than that in DI group.The expressions of GLUT4 mRNA in DI resembled ones in EL, EH and HI groups, among them there were no significant difference.Conclusion:Endurance training can increase gene expressions of GLUT4 in skeletal muscle of diabetic rats, and the intensity of exercise does not significantly contribute to the expressions of GLUT4 mRNA. The results also show that integrative interventions with low-intensity training plus insulin injection which had maximal expressions of GLUT4 gene can not be replaced by other individual intervention.