Cardiac hypertrophy in response to interval training with emphasis on PI3K expression in heart tissue of rats with induced obesity

The importance of obesity in chronic diseases such as type 2 diabetes and cardiovascular diseases is well known. This study aimed to assess the effect of high intensity interval training (HIIT) on PI3K expression in cardiac tissue in obesed rats with high fat diet (HFD).

For this purpose, from 21 male Wistar rats aged 10 week (220 – 10 g), 14 rats obesed by 6 weeks high-fat diet (HFD) were randomly divided to control obese (n=7) or exercise obese (n=7) groups. Also, 7 rats with normal weight were selected as normal group. The exercise rats were completed 8 weeks HIIT (5 times weekly) in the form of interval runs on the treadmill. The control obese and normal groups did not participate in the exercise program. 48 hours after the lasting exercise session, PI3K expression in cardiac tissue, the heart/body weight ratio and left ventricular/heart weight ratio were compared by One-Way ANOVA and Tukey post hoc test between groups (P< 0.05).

On the other hand, HIIT resulted in significant increase in PI3K expression in heart tissue (P = 0.001), heart/body weight ratio (P = 0.027) and left ventricular/body weight ratio (P = 0.015) in obese compared to control rat groups.

Based on these data, cardiac hypertrophy in response to HIIT may be attributed to increased PI3K expression in heart tissue. Understanding the mechanisms responsible for the effect of exercise on cardiac hypertrophy requires more studies.