The Effect of High-intensity Interval Training and Moderate-intensity Continuous Training on Oxidative Stress Markers in Left Ventricular Tissue of Male Rats

Objectives: The present study aimed to assess and compare the effects of high-intensity interval training and moderate-intensity continuous training on oxidative stress-related markers in the left ventricular tissue of the heart muscle in healthy male rats. Methods: Fifteen male Wistar rats, aged ۵۰-۷۰ days, were randomly divided into ۳ groups: Control group (CON), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT). After determining the maximum speed of VO۲max, the training program of HIIT (six ۲-min periods with ۸۵%-۹۰% VO۲max and five ۲-min with ۵۰%-۶۰% VO۲max intensity) and MICT (same distance of running as HIIT with ۷۰% VO۲max intensity) groups were performed for ۸ weeks, ۵ days per week. Forty-eight hours after the last intervention session, the animals were anesthetized, and their heart tissue was removed and stored at -۸۰°C. Then, the expression rates of peroxisome proliferator-activated receptor-γ coactivator-۱α (PGC-۱α), AMP-activated protein kinase (AMPK), and superoxide dismutase (SOD) genes were measured by real-time PCR, and the concentration of malondialdehyde (MDA) in left ventricular tissue of heart was measured by colorimetry method. One-way analysis of variance and Tukey post hoc test were used for data analysis at the significance level of P<۰.۰۵. Results: There were significant differences between the groups’ expression rates of AMPK, PGC-۱α, and SOD (P<۰.۰۵). The expression rates of AMPK and PGC-۱α were higher in the MICT group than in the CON group (P<۰.۰۵). No significant difference was observed between HIIT and MICT groups regarding AMPK and PGC-۱α (P>۰.۰۵). SOD expression was significantly higher in the HIIT group than CON and MICT groups (P<۰.۰۵). SOD expression was also higher in the MICT group compared to the CON group (P<۰.۰۵). MDA concentration was not significantly different between the studied groups (P>۰.۰۵). Discussion: HIIT and MICT induce positive adaptations in the expression of AMPK, PGC-۱α, and SOD in the heart tissue of healthy male rats. However, HIIT stimulates SOD gene expression more than MICT.

Keywords:

Exercise training , Cardiomyocytes , Oxidative stress , Peroxisome proliferator-activated receptor gamma coactivator ۱-alpha , AMP-activated protein kinase kinases