Changes in Mitochondrial Dynamic Factors (mfn2 and drp1) Following High Intensity Interval Training and Moderate Intensity Continuous Training in Obese Male Rats

Abstract

Objective: Mitochondrial content and function are important determinants of oxidative capacity and metabolic efficiency of skeletal muscle tissue. The aim of this study was to investigate the changes in mitochondrial dynamic factors (mfn2 and drp1) following high intensity interval training (HIIT) and moderate intensity continuous training (MICT) in obese male rats. Materials and Methods: In this experimental study, 40 male wistar rats after inducing obesity with high fat diet (for 10 weeks), eight rats from the high-fat diet group (O) and eight rats of the standard dietary group (C) were sacrificed and other obese rats were randomly divided into three groups: obesity control (OC), MICT and HIIT groups. The HIIT protocol includes 10 bouts of 4-minute activity with intensity of 85-90% vo2max and 2-minute active rest periods and MICT protocol with intensity of 65-70% VO2max with covered distance was matched to that of HIT protocol for 12 weeks and 5 sessions per week. Protein levels of mfn2 and drp1 soleus muscle were measured by Western blot. For analyzing the data, One-way ANOVA and Tukey post hoc with SPSS–23 and the significance level was P-value≤ 0.05. Results: Induction of obesity was associated with a significant decrease in soleus muscle mfn2 and drp1 (P-value= 0.001). The intervention of HIIT and MICT significantly increased of mfn2 and drp1 compared to control group (P-value= 0.001). Also, mfn2 and drp1 were significantly higher in HIIT compared to MICT group (P-value= 0.001). Conclusion: It seems that HIIT and MICT increase the mitochondrial dynamic factors in skeletal muscle, and the effects of HIIT are significantly higher.