The effect of eight weeks of high-intensity interval training with caloric restriction on the expression of SIRT1, ERRα and PDK4 genes in the liver of male Wistar rats: Comparison of high-fat diet and standard diet

A calorie restriction diet is one way of the ways to reduce calorie intake without malnutrition. The purpose of this study was to investigate the effect of eight weeks of high-intensity interval training with calorie restriction of high-fat or standard diet regimens on the expression of sirtuin 1 (SIRT1), estrogen-related receptor alpha (ERRα) and pyruvate dehydrogenase kinase 4 (PDK4) in the liver of male Wistar rats.

48 rats were randomly divided into six groups (n=8): control, high-intensity interval training, high-fat diet with caloric restriction, standard diet with caloric restriction, standard diet with caloric restriction + interval training, and fatty diet with caloric restriction + interval training were divided. High-intensity interval training was performed for 8 weeks and 5 days a week with an intensity of 90 to 100% of the maximum speed in the form of running on a treadmill. Expression of SIRT1, ERRα and PDK4 genes in liver tissue was measured by Real-Time PCR method and one-way ANOVA statistical method was used to compare between groups.

Interval training led to a significant increase in ERRα gene expression compared to the control group (p=0.001). Fatty diet with calorie restriction significantly decreased SIRT1 gene expression compared to standard diet with calorie restriction (p=0.002). Also, eight weeks of standard diet with caloric restriction led to a significant increase in PDK4 gene expression compared to the control group (p=0.02).

In the condition of calorie restriction, periodic exercise through the up regulation of ERRα gene expression may play a key role in increasing hepatic gluconeogenesis. Interestingly, high-fat diet may have negative effects on the liver even under caloric restriction by reducing the expression of SIRT1, which plays an important role in the antioxidant capacity of the liver.