Effect of High Intensity Interval Training on Apoptotic Gene Expression in Rat Myocardial Tissue
Background: Excessive apoptosis in the myocardium contributes to the pathogenesis of heart disease. Evidence indicates that high intensity interval training (HIIT) can alter myocardial apoptosis related signaling. Objectives: The purpose of the study was to investigate the effect of 12 weeks of HIIT on some indices of apoptosis, including Bcl 2, Bax, and caspase 3 in the myocardial tissue of male rats. Methods: Thirty male Wistar rats (age range: 8 10 weeks) were randomized into three groups, including sham (n 10) control (n 10) and HIIT (n 10) The experimental group underwent HIIT consisting of 2 8 repetitions of 4 min high intensity intervals (85% 90% peak speed) interspersed with low intensity intervals (45% 50% peak speed) performed five times/week over 12 weeks. Forty eight hours after the last training session, animals' hearts were removed. The gene expressions of Bcl 2, Bax, and caspase 3 were analyzed by the RT PCR method. The independent t test was used for statistical analysis (P 0.05) Results: The gene expressions of Bcl 2 and Bcl 2/Bax ratio were higher in the training group than in the control group (P 0.001 and P 0.002, respectively) Regarding Bax and caspase 3 gene expression, although the mean levels were lower in the exercise group than in the control group, the differences were statistically insignificant (P 0.57 and P 0.27, respectively) Conclusions: Overall, it seems that HIIT significantly increases the expression of anti apoptotic indicator Bcl 2 and the ratio of Bcl 2/Bax in the myocardium of male rats. However, further studies are needed to show the effects of HIIT on myocardial apoptosis.