The Effect of Aerobic Exercise on the Function of Local Renin-Angiotensin System and Insulin Resistance in the Gastrocnemius Muscle of Type 2 Diabetic Mice

The purpose of this study was to investigate the impact of aerobic exercise on the function of local renin-angiotensin system and insulin resistance in the Gastrocnemius muscle of type 2 diabetic mice.

The number of 18 male C57BL/6 mice were divided into two groups: 1. Mice fed with a standard diet for 12 weeks (control group), 2. Mice fed with a high-fat diet for 12 weeks with streptozotocin injection (diabetes group). Diabetic mice were randomly divided into two groups: 1. Diabetes-Sedentary group, 2. Diabetes-exercise group. The mice of the training group exercised on the treadmill for eight weeks and five days/week with an average speed of 19 m/min and for 45 minutes. 24 hours after the last training session, the mice were sacrificed. The Gastrocnemius muscle tissue was extracted and stored in -80°C freezer to measure the expression level of angiotensin 2, Mass receptor, At1 receptor and glucose transporter 4 (Glut 4).

The results showed that the expression of Mass and Glut4 receptor in diabetes-exercise mice was significantly higher than diabetes-sedentary group. Also, the expression of angiotensin 2, HOMA-IR, and fasting glucose in the muscle of diabetes-exercise mice were significantly lower vs. diabetes-sedentary mice. Also, the expression of At1 receptor in the diabetes-exercise group was insignificantly lower than in the diabetes-sedentary group.

The findings of the present study show the important role of exercise in improving the local renin-angiotensin system in skeletal muscle. Eight weeks of aerobic training can reduce muscular insulin resistance and improve type 2 diabetes by decreasing the expression of angiotensin 2, At1 receptor and increasing the Mass receptor.