The effect of a period of high-intensity interval training on gene expression of transforming growth factor-beta (TGF-β1) and the size of cells in subcutaneous adipose tissue of rats fed with high-fat diet

The effect of exercise in reducing fat tissue and fat cell size may be related to TGF-β1 signaling. This study aimed to investigate the effect of high-intensity interval training (HIIT) simultaneously with high-fat diet on TGF-β1 gene expression and cell size in the subcutaneous adipose tissue of rats.

In this study, 24 adult male rats were randomly divided into 4 groups: ND (normal diet), HFD (high fat diet), HIIT+ND and HIIT+HFT. HIIT consisted of eight bouts of intense activity at 90% of maximum running capacity (MRC) for 2.5 minutes, with active rest periods at 50% of maximum running capacity for 2.5 minutes for 10 weeks. 48 hours after the last training session, blood was taken and subcutaneous fat was removed. qRT-PCR method was used to measure TGF-β1 gene expression and the stereological method was used to determine the size of fat cells. Two-way ANOVA test with a significant level of P < 0.05 was used to analyze the data.

The interaction between HIIT and high-fat diet caused a significant decrease in TGF-β1 gene expression (F=24.99, P<0.001), but it had no significant effect on fat cell size (P=0.780, F=0.07). A positive and significant correlation was observed between TGF-β1 gene expression and fat cell size (r=0.896, P<0.001).

HIIT at the same time with consuming a high-fat diet prevents the increase of TGF-β1 in the subcutaneous fat tissue and may have a preventive effect on the increase in fat cell size.