The effect of 8-week resistance training on IRS-1 gene expression in gastrocnemius muscle and glycemic profile in diabetes rats

Abstract

Background: The insulin receptor substrate-1 (IRS-1) has an important role in insulin signaling pathways in the target tissue of obese or insulin-resistant individuals. This study aimed to assess the effect of resistance training on fasting glucose, insulin resistance, and IRS-1 gene expression in gastrocnemius muscle in male Wister rats with type 2 diabetes (T2D). Materials and Methods: For this purpose, T2D induced by high- fat diet (8 weeks) and STZ in fourteen male Wistar rats (220 ± 10 g) and then assigned into exercise (resistance training, 8 weeks, 5 days/weekly, n = 7) and control (no-training, n = 7) by randomly. Fasting blood samples were obtained for measuring glucose, insulin, and calculating insulin resistance (HOMA-IR).  Also, the IRS-1 gene expression in gastrocnemius muscle was measured 48 hours after the last training session of both cases and controls. Results: Compared to control, IRS-1 gene expression in gastrocnemius muscle increased significantly by resistance training in exercise groups (p = 0.001). Fasting glucose (p < 0.001) and insulin resistance (p = 0.007) were reduced in the exercise rats compared to the control group. Conclusion: Based on the results, improved fasting glucose and insulin function after resistance training in T2D diabetes could be attributed to enhancing IRS-1 expression in gastrocnemius muscle by training.