Effect of 6-week interval training on Insulin receptor substrate 1 (IRS-1) expression in gastrocnemius muscle and insulin resistance in Wistar obese rats

The purpose: Apart from the metabolic and hormonal components, genetic factors disorder play an important role in insulin function in target tissues. The aim of this study was to determine the effect of 6 week interval training on type 1 insulin receptors (IRS1) expression, fasting glucose levels and insulin resistance in obese male rats.Methods: in present experimental-practical study, 14 male Wistar rats that fattened by a high-fat diet (6 weeks), were randomly assigned to control (without training) and exercise (interval training) groups. The exercise group performed 5 sessions per week for 6-weeks interval training. 48 hours after the last exercise session, fasting glucose levels, serum insulin, insulin resistance, and expression of IRS1 in the gastrocnemius muscle were measured in both groups. Data analysis was performed by independent t-test. Changes were less than 5% Was considered significant.Results: interval training were associated with fasting glucose (p <0.001) and insulin resistance (p <0.001) reduction in the exercise group compared with control group. Furthermore, interval training induced significantly increased in IRS1 expression in gastrocnemius muscle of exercise group compared to control group (p = 0.016). There was also a significant reverse relationship between change in relative expression and insulin resistance in response to exercise program (p = 0.019).Conclusion: improvements in Glycemic profiles and insulin resistance in obese rats following long-term interval training can be attributed to increased in expression of IRS1 in muscle tissue of the trained muscle.

Keywords:

interval training , obesity , gen expression , insulin resistance