The effect of eight weeks of high-intensity interval training on p-mTOR, T-mTOR and fibrosis of cardiac tissue and insulin resistance in diabetic male Wistar rats

The mechanistic target of rapamycin (mTOR) protein complex increases in response to resistance training with a histological approach and decreases in aerobic training with a metabolic approach. These changes can be discussed in the conditions of type 2 diabetes (T2DM) and with exercise. Therefore, taking into account exercises such as high-intensity interval training (HIIT) with aerobic and anaerobic characteristics and on the other hand T2DM intervention can depict the possible interaction of mTOR with glycemic and histopathological indicators of the cardiac. So, the present study was conducted to determine the effect of eight weeks of HIIT on p-mTOR, T-mTOR and fibrosis of cardiac tissue and insulin resistance on diabetic rats through STZ injection.

Twenty male adult white Wistar rats were divided into four groups (N=5): healthy control, diabetic control, healthy workout and diabetic workout. The HIIT protocol was carried out five sessions a week for eight weeks on a treadmill. One-way analysis of variance was used for statistical analysis at a significance level of P < 0.05.

The results showed that eight weeks of HIIT did not lead to significant changes in the amount of p-mTOR and T-mTOR in the cardiac tissue of rats with T2DM (P > 0.05); However, it caused a significant decrease in insulin resistance (31.2% compared to the diabetic control group) and cardiac tissue fibrosis (51.6% compared to the diabetic control group) in rats with T2DM (P < 0.05).

According to the results, it seems that eight weeks of HIIT is enough to observe the increase in amount of cardiac tissue mTOR in healthy rats, but it is insufficient in rats with T2DM. Also, it is possible that the reduction of cardiac tissue fibrosis in rats with T2DM, at least during eight weeks of HITT, is independent of cardiac tissue mTOR.