The Effect of resistance training on GLUT4 expression in muscle tissue, glucose and insulin resistance in rats

Introduction: One of the most important glucose transporters is glucose transporter 4 (GLUT4), which can be expressed in insulin-sensitive tissues such as skeletal muscles. The purpose of this study was to investigate the effects of resistance training on GLUT4 gene expression and glycemic index in rats with type 2 diabetes. Materials & Methods: Twenty-seven Wistar rats were selected; the rats were fed a high-fat diet for 6 weeks and then randomly divided into three groups: diabetic with resistance training (n=10), diabetic control (n=10), and obesity control (n=7). Type 2 diabetes was induced by injection of a low dose of Streptozotocin (STZ) (30 mg/kg). The resistance training program was performed for 6 weeks, five days per week. The glucose concentration was measured by glucose oxidase enzyme technology, serum insulin by the ELISA method, and real-time PCR was used to test the GLUT4 gene expression. For data analysis, independent t-test and one-way analysis of variance were used (α=0/ 05). Findings: The results indicated that induction of diabetes reduced the GLUT4 gene expression in the gastrocnemius muscle tissue of diabetic rats (P=0.001). Also, GLUT4 gene expression increased in the diabetic training group compared with the diabetic control group (P=0.038). In addition, blood glucose and insulin resistance decreased significantly. The content of GLUT4 gene expression was increased in the training group compared with the diabetic control group (p=0.001). Discussion & Conclusions: Based on the findings of this study, it can be stated that the GLUT4 gene expression in rat gastrocnemius muscle tissue is reduced in diabetic rats. Also, resistance training could increase the GLUT4 gene expression and improve glucose transport and insulin resistance in type 2 diabetic rats. This could be due to improvement in the performance of glucose transporters by resistance training