耐力训练对糖尿病大鼠骨骼肌p38信号激酶的调节作用

Effects of endurance training on the activities of p38 mitogen-activated protein kinase pathways in skeletal muscle of diabetic rats

目的:研究不同强度的耐力训练对糖尿病大鼠骨骼肌细胞丝裂素活化蛋白激酶p38活性的调节作用,为制订适宜的糖尿病运动疗法程序提供分子生物学依据。方法:雄性SD大鼠34只,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(E1,n=6)、高强度运动组(E2,n=6)、低强度运动加胰岛素治疗组(EI1,n=6)、高强度运动加胰岛素治疗组(EI2,n=6)、非胰岛素治疗非运动组(C,n=5)和胰岛素治疗非运动组(CI,n=5)。耐力训练采用活动平板,胰岛素皮下注射,共8周。运用化学发光法测定p38活性。结果:训练8周前后,EI1组安静血糖下降46%(P<0.01),其余各组血糖无明显下降。单次运动前后E1组、EI1组、EI2组和CI组血糖均见明显下降,其中EI1组血糖降低尤为显著达83%(P<0.01)。骨骼肌p38活性在EI1组显著高于其余各组(P<0.05),E1组显著高于E2组、C组、CI组(P<0.05)。结论:低强度运动训练以及低强度运动训练加胰岛素治疗均能显著提高糖尿病大鼠骨骼肌细胞p38信号激酶,提示低强度运动训练加胰岛素治疗是内源性胰岛素缺乏性糖尿病的适宜治疗方案。

Objective:To determine the effects of different intensities of endurance training on the activation of p38mitogen-activated protein kinase(MAPK)pathways in skeletal muscle of diabetic rats.Method:Thirty four of male Sprague-Dawley rats were modeled for diabetes by streptozotocin injection.The diabetic rats were randomly divided into six groups:low-intensity training(E 1 ,n=6),high-intensity training(E 2 ,n=6),low-intensity training with insulin injection(EI 1 ,n=6),high-intensity training with insulin injection(EI 2 ,n=6),control without insulin injection and training(C,n=5)and control with insulin injection and no training(CI,n=5).The animals with endurance training were forced to running on motorized treadmill for8weeks.The rats with insulin were subcutaneously injected for8weeks.Activities of p38kinase in skeletal muscle were measured by a nonradioactive method.Result:The levels of quiet blood glucose in rats with EI 1 decreased significantly to46%after endurance training for8weeks comparing to that before endurance training(P<0.01),which was not found in other groups.The levels of blood glucose in rats with E 1 ,EI 1 ,EI 2 and CI declined remarkably after a bout of exercise.Especially,the blood glucose of rats with EI 1 decreased to83%(P<0.01).The activity of p38kinase in skeletal muscle of rats with EI 1 increased significantly after endurance training for8weeks compared with other groups(P<0.05).The p38activity in skeletal muscle of rats with E 1 was significantly higher than that in E 2 ,C and CI(P<0.05).Conclusion:Both low-intensity training and low-intensity training plus insulin injection may significantly increase activity of muscle p38MAPK in diabetic rats,which suggests that therapeutic prescription on low-intensity training plus insulin injection be very suitable for the diabetes mellitus induced by a deficient supply of endogenous insulin.