有氧运动对2型糖尿病大鼠骨骼肌ERK1/2活性的影响

The effects of aerobic exercise on ERK1 /2 activity in skeletal muscle of type 2 diabetic rats

目的:观察有氧运动对2型糖尿病大鼠骨骼肌细胞外信号调节激酶(ERK1/2)活性的影响,探讨有氧运动对2型糖尿病的预防和调控机制。方法:将75只SD大鼠随机分为正常对照组(CON)、糖尿病对照1组(DC1)、糖尿病运动1组(DE1)、糖尿病对照2组(DC2)、糖尿病运动2组(DE2)5组(n=15)。正常对照组用普通饲料喂养,糖尿病组用高脂高糖配方饲料喂养。经过8周高脂高糖喂养后,糖尿病2组大鼠腹腔内注射链脲佐菌素(STZ),诱发2型糖尿病;糖尿病运动1组游泳的最后1周初和糖尿病对照1组同时注射STZ,注射剂量为35mg/kg,3 d后尾部取血测血糖≥16.7 mmol/L为造模成功。运动干预8周后,测定大鼠血清胰岛素、骨骼肌中ERK1/2蛋白表达等指标。结果:(1)与正常对照组比较,糖尿病各对照组血液中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)、游离脂肪酸(FFA)显著升高(P<0.05,P<0.01),空腹血糖(FBG)、胰岛素(FIN)含量和胰岛素抵抗指数(HOMA-IR)显著升高(P<0.01),ERK1/2磷酸化的蛋白表达显著下降(P<0.05),糖尿病对照2组ERK1/2蛋白含量显著下降(P<0.05);(2)8周游泳运动后,与糖尿病对照组比较,糖尿病运动组血液中TC、TG、FFA、LDL-C显著下降(P<0.05),FBG、FIN、HOMA-IR显著下降(P<0.05,P<0.01),ERK1/2磷酸化蛋白表达显著升高(P<0.05)。结论:长时间有氧运动,增加了骨骼肌ERK1/2磷酸化水平,改善了2型糖尿病大鼠胰岛素抵抗的状况,降低血糖。这可能是改善糖代谢紊乱,提高胰岛素敏感性的机制之一。

Objective： To observe the effects of aerobic exercise on activity of extracellular signal-regulated kinase（ ERK1 /2） in skeletal muscle of type 2 diabetic rats and explore the prevention and control mechanism of aerobic exercise on type 2 diabetes. Methods： Seventy five SD rats were randomly divided into： normal control group（ CON） including 15 rats was fed with normal diet,diabetes control group 1（ DC1）,diabetes exercise group 1（ DE1）,diabetes control group 2（ DC2）,diabetes exercise group 2（ DE2）. Diabetes model group were fed with high-fatty and high-sugar diet. The diabetes model rats were fed with high-fatty and high-sugar diet for 8weeks,. Diabetes group 2 rats were injected intraperitoneal streptozotocin（ STZ） to induce type 2 diabetes. At the early stage of last swimming week,diabetes exercise group1 and diabetes control group 1 were injected with STZ（ 35 mg / kg） at the same time,After three days,if the level of blood glucose was ≥16. 7mmol / L,the model was successful. After 8 week-interventions,all the rats were killed,the serum levels of insulin and the expression of ERK1 /2 protein in skeletal muscle were determined. Results：（1）Compared with the normal control group,the levels of total cholesterol（ TC）,triglyceride（ TG）,low density lipoprotein cholesterin（ LDL-C）,free fatty acid（ FFA）,fasting blood-glucose（ FBG）,fasting insulin（ FIN） and insulin resistance index（ HOMA-IR） were increased significantly in diabetes control group（ P〈0. 05 or 0. 01）. However,the expression of ERK1 /2 phosphorylation protein was decreased obviously in diabetes control group. The content of ERK1 /2 protein was decreased obviously in diabetes control group 2 had（ P〈0. 05）.2. After eight weeks＇ swimming,compared with the diabetes control group,the levels of TC,TG,FFA,LDL-C,FBG,FIN and HOMAIR were decreased significantly in diabetes exercise group（ P〈0. 05 or 0. 01）. At the same time,the expression of ERK1 /2 phosphorylation protein was increased obviously in diabetes exercise group（ P〈0. 05）. Conclusion： Long-term aerobic exercise can improve the skeletal muscle ERK1 /2 phosphorylation and insulin resistance of type 2 diabetic rats,thereby lowering blood glucose. It is probably one of the mechanisms to improve glucose metabolism disorders and insulin sensitivity.