Effect of Eight Weeks of High-Intensity and Low-Intensity Interval Training on Chemokine Gene Expression and Vascular Endothelial Growth Factor in Male Adult Rats

During exercise, angiogenesis occurs in active skeletal muscle; however, little is known about potential mechanisms for improving this adaptation. This study aimed to investigate a period of interval training on chemokine gene expression and its effect on vascular endothelial growth factors in male adult rats.

In this study, 24 rats were divided into three groups (n=8 in each): high-intensity training (HIT), low-intensity training (LIT), and control groups. HIT and LIT groups were trained for eight weeks (five days per week). The exercise program in the HIT group consisted of running on a treadmill for 8 min with 85-90% VO2max intensity and 2 min with 50-60% VO2max intensity. The LIT group exercise program consisted of running on a treadmill for 8 min with 55-60% VO2max intensity and 2 min with 45-50% VO2max intensity. The control group had no training. The expression of chemokine and vascular endothelial growth factor genes was measured in soleus muscle. The data were analyzed using one-way ANOVA and Tukey post hoc test. Statistical differences were considered significant at P<0.05.

The results of this study, showed that the expression levels of chemokine and vascular endothelial growth factor gene in the HIT group were significantly higher than that in the control group (P=0.01, P=0.04), while the levels of chemokine and vascular endothelial growth factor in the LIT group were not significantly different from those in the control group (P=0.2, P=0.1).

According to the results of the present study, it seems that high-intensity exercises can be more effective than low-intensity exercises in increasing angiogenesis caused by the increase of chemokine that in turn depends on vascular endothelial growth factor levels.