The effect of 4 weeks high-intensity interval training (HIIT) on the content of downstream and upstream mTORC1 pathways gastrocnemius muscle of type 2 diabetic rats

Background: The pathway of mTORC1 is one of the most important pathway in protein synthesis, and type 2 diabetes and insulin resistance can lead to inhibit this pathway. The aim of this study was to investigate the effect of 4 weeks high-intensity interval training (HIIT) on the content of downstream and upstream mTORC1 pathways in gastrocnemius muscle in type 2 diabetic rats. Materials and methods: In this experimental study, 16 Sprague-Dawley male rats (with mean weight of 250 ± 20 gr) were selected and after induction of diabetes by streptozotocin and nicotinamide, the rats were randomly assigned into two groups, including diabetic HIIT training and diabetic control. The experimental group performed 4 days a week the exercise training for 4 weeks, while the control group did not have any training program. Independent T-test was used to analyze the data. Results: A significant change was not observed in the total content of AKT1 proteins (p<0.31), P70S6K1 (p<0.69) and 4EBP1 (p<0.84) in the HIIT training group compared to the control group, but the total protein content of mTOR (p<0.02) and the form of phosphorylation of AKT1 (p<0.03), mTOR (p<0.03), P70S6K1 (p<0.02) and 4EBP1 (p<0.009) proteins showed significant increase in training group compared to the control group. Conclusion: The HIIT training can probably activate the pathway of AKT1/mTOR/P70S6K1 and AKT1/mTOR/4EBP1 in the mTORC1 pathway; therefore, the HIIT training can lead to protein synthesis or muscle hypertrophy through this pathway in the gastrocnemius muscle of the trained rats