Effect of Eight Weeks of Exercise with Different Intensities on the Gene Expression of Decorin and Muscular TGF-β in the Male Adult Rats

 This study aimed to investigate a period of exercise activity with different intensities on decorin gene expression through interaction with transforming growth factor-beta (TGF-β) in male adult rats.

 This experimental study included 24 males adult Wistar rats that were divided into three groups (8 animals per group) of High-Intensity Training (HIT), Low-Intensity Training (LIT), and Control. Training groups trained for eight weeks and five days a week. The HIT group exercise program consisted of one hour of exercise for five 8-min intervals at 85%-90% Vo2max that were separated by 2-min intervals with an intensity of 50%-60% Vo2max. On the other hand, the LIT group exercise program included five 8-min intervals with an intensity of 55%-60% Vo2max, and 2-min intervals with an intensity of 45%-50% Vo2max. It should be noted that the control group received no exercise program.

 The results of this study showed that the expression levels of the decorin gene in the HIT training group were significantly higher than those in the control group (P=0.001), whereas the levels of decorin in the LIT training groups were not significantly different from those in the control group (P=0.11). The expression levels of the TGF-β gene in both training intensities (high- and low-intensity training, respectively) showed a significant difference, compared to the control group (P=0.001, P=0.18).

 According to the results of the present study, it seems that HIT exercise can lead to a greater increase in muscle growth due to increased TGF-β-dependent myokine, compared to LIT exercise.