运动对糖尿病大鼠骨骼肌葡萄糖运载体基因表达的影响

Effect of exercise on glucose transporter gene expression in diabetic rat skeletal muscle

目的研究运动对链脲佐菌素引起的糖尿病大鼠骨骼肌细胞内葡萄糖运载体４（ｇｌｕｃｏｓｅｔｒａｎｓ－ｐｏｒｔｅｒ，ＧＬＵＴ４）基因表达的作用。方法实验大鼠分为３组：（１）糖尿病非运动组；（２）糖尿病运动组；（３）正常对照组。每组６只大鼠。糖尿病运动组大鼠进行６周游泳训练。用斑点杂交法检测３组大鼠骨骼肌细胞内ＧＬＵＴ４ｍＲＮＡ含量。结果糖尿病大鼠骨骼肌细胞内ＧＬＵＴ４基因表达明显降低，ＧＬＵＴ４ｍＲＮＡ含量与正常对照组相比减少５４．９％。糖尿病运动组大鼠经过６周运动训练，血糖由１８．５±１．９ｍｍｏｌ／Ｌ降至１４．０±３．３ｍｍｏｌ／Ｌ（ｔ＝４．６４，Ｐ＜０．０１），骨骼肌细胞内ＧＬＵＴ４ｍＲＮＡ含量与糖尿病大鼠相比增加５６％（ｔ＝１５．５６，Ｐ＜０．０１）。结论在糖尿病高血糖状态下，大鼠骨骼肌细胞内的ＧＬＵＴ４基因表达受到抑制，这可能是胰岛素抵抗受体后缺陷的重要原因。运动训练能够促进糖尿病大鼠受抑的ＧＬＵＴ４基因表达的部分恢复，这可能是运动增加外周组织对胰岛素的敏感性，降低血糖的机制之一。

Objective To investigate the effect of the exercise on glucose transporter 4 (GLUT4) gene expression in skeletal muscles of rats with streptozotocin induced diabetes.Methods Three experiment groups of rats were investigated: diabetic non exercise group; diabetic exercise group; and normal controls. Diabetic exercise rats were swim trained for 6 weeks. The GULT4 mRNA of skeletal muscle cells was determined with dot blot.Results There was weak gene expression of GULT4 in diabetic rats, and dot blot revealed that the GLUT4 mRNA decrease 54.9% in skeletal muscle cells compared with the normal control. After 6 weeks exercise training, the hyperglycemia of diabetic exercise rats decreased significantly (from 18.5±1.9 mmol/L to 14.0±3.3 mmol/L, t =4.64 P <0.01). In muscle cells of diabetic exercise rats, the GLUT4 mRNA increased 56% as compared with the diabetic rats ( t =15.56, P < 0.01). Conclusion Chronic hyperglycemia may inhibit the gene expression of GLUT4 in diabetic rats, which caused the post receptor insulin resistance in peripheral tissue. Exercise training can improve the impaired GLUT4 expression in diabetic rats, which may contribute to the mechanisms of enhanced insulin sensitivity and decreased hyperglycemia in diabetes mellitus.