Effect of High-Intensity Interval Training following Ischemia-Reperfusion Injury in Heart on Hand 2 and Phosphatidylinositol-3-Kinase Genes in Male Rats

Introduction: Experimental and clinical studies have shown that exercise training is one of the most effective strategies for reducing the progression of cardiomyopathy and decreasing the incidence of cardiovascular complications and mortality due to myocardial ischemia. This study aimed to investigate the role of high-intensity interval training (HIIT) in the expression of Hand2 and Phosphatidylinositol-3-kinase (PI3K) genes in cardiac ischemia rats. Materials & Methods: In this study, 28 male Wistar rats (200-250 g) were randomly divided into four groups of sham, ischemia, exercise, and exercise-ischemia. Myocardial infarction was performed by the closure of the left anterior descending artery for 30 min. In total, 40-min HIIT (each interval consisted of 4-min very high intensity running with approximately 85% to 90% maximum rate of oxygen consumption [VO2max] followed by 2-min active recovery with approximately 50% to 60% VO2max) were performed three days a week for eight weeks. Ethics code: IR.SSRI.REC.1396.134 Findings: The results showed that the expression level of the Hand2 gene in the ischemia-training group was significantly increased, compared to the sham (P=0.001) and ischemia (P=0.001) groups. Furthermore, the concentration of PI3K in the exercise and exercise-ischemia groups was significantly increased, compared to the sham (P=0.001) and ischemia (P=0.001) groups. However, there was a decrease in the ischemia group, compared to the other groups (P<0.05). Discussions & Conclusions: The findings of the present study showed that HIIT leads to increased expression of the Hand2 gene and PI3K. Furthermore, the HIIT results in physiological hypertrophy. On the other hand, the pathological hypertrophy of these variables is reduced in this study.