The effects of mid- and long-term endurance exercise on heart angiogenesis and oxidative stress.

OBJECTIVES: Long-term, irregular endurance exercise may result in disturbance to the angiogenesis of heart muscles and blood supply. The aim of the present study is to evaluate the effects of mid- and long-term endurance exercise on the process of angiogenesis. MATERIALS AND METHODS: Eighteen male Wister rats of 220±10 g, were randomly assigned to three groups of 6 rats including: Control, Mid, and Long Group. After the training sessions, the rats were weighed and sacrificed. RESULTS: In comparison to the Control Group, the both groups, indicated remarkable increase in the weight of heart and significantly higher serum LDH and CK activity (P<0.01). In addition, after the training sessions, weakened antioxidant heart system (TAC, total thiol groups, and GPX activity) and increased oxidative stress markers (MDA and NO) were remarkably observed in Mid Group and particularly in those in the Long Group in comparison to the Control Group (P<0.05). Finally, significant increase in VEGF-B, MEF-2C and MMP-2 gene expression was found for both experimental groups, associated with the up-regulation of ANGPT-1 and HDAC4 in the Mid Group (P<0.05). While the longer exercise period induced significantly upper VEGF-B, MEF-2C, and MMP-2 and significantly lower ANGPT-1 and HDAC4 in the Long Group (P<0.05). CONCLUSION: In this study, higher oxidative status and upper angiogenic gene expression with higher VEGF-B, MEF-2c, and MMP-2 and lower ANGPT-1 and HDAC4 were traced as effects of long-term endurance exercise. These results point to the dis-regulation of blood supply in the presence of angiogenesis resulting from long-term exercise.