Effect of High-Intensity Interval Training on Apoptotic Gene Expression in Rat Myocardial Tissue

Abstract

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.

The Effect of High Intensity Interval Training on the Intrinsic and Extrinsic Pathways of Myocardial Apoptosis in Diet-Induced Obese Rats

“…In the meantime, Bax and Bcl2 proteins are involved in the formation of apoptosis and mitochondrial apoptotic signaling as the main proteins. Increasing Bcl2 and, consequently, decreasing the Bax/ Bcl2 ratio is one of the most important factors to avoid mitochondrial membrane damage as well as to prevent apoptosis (20). To date, no studies have been conducted to investigate the effect of HIIT training on cardiac apoptosis in obese subjects, and the results obtained by similar studies on non-obese subjects and other tissues are often contradictory.…”

“…The OC group was excluded from participating in any training intervention until the end of the course. The OT group was subjected to a high-intensity interval training program performed 5 sessions per week over 12 weeks (Table 1) (20). The treadmill speed was increased by five percent each week to meet the principle of overload.…”

Response of Cardiac Tissue β-catenin and GSK-3β to Aerobic Training and Hyaluronic Acid in Knee OA Model Rats

“…Shin Fujimaki et al reported that chronic running activated the satellite cells in the diabetic mice, improving the Wnt signaling pathway (28). Pourrazi et al showed that by affecting Wnt signaling, exercise activity improved the process of muscle mass loss due to dietary restriction (29). In this regard, some reports have suggested that GSK-3β can either directly activate the phosphorylation of pre-apoptotic proteins such as Bax or increase the expression of Bim (30,31).…”