Influence of Exercise Intensity on the Expression of Angiogenesis-Related Genes in the Hearts of Male Rats

Angiogenesis, the formation of new capillaries from pre-existing vessels, crucially involves activation of the hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF) genes. This study investigates the impact of exercise intensity on the expression of angiogenic genes in the hearts of male rats.

Eighteen male Wistar rats were randomly assigned to three groups: High-Intensity Interval Training (HIIT), Continuous Training (CT), and control (C). Both HIIT and CT groups underwent 8 weeks of training with five sessions per week. Anesthesia and blood sampling occurred 48 hours post final training session. Gene levels of HIF-1 and VEGF were measured in the left ventricle. Data analysis employed ANOVA and LSD post hoc tests (P≤0.05).

VEGF gene expression significantly increased in both HIIT and CT groups compared to the control group (P = 0.001), with a more pronounced elevation in the HIIT group than the CT group (P = 0.004). Furthermore, HIF-1 levels exhibited a significant reduction in both HIIT (P = 0.001) and CT (P = 0.001) groups compared to the control group, with the HIIT-induced decrease surpassing that of the CT group (P = 0.049).

The noteworthy elevation in VEGF and decrease in HIF-1 gene expression levels in trained rats imply that exercise training enhances angiogenesis. Importantly, the extent of this enhancement is contingent upon exercise intensity, with HIIT demonstrating more pronounced positive effects on VEGF levels.