A Study on the Serum Levels of Angiogenic Factors in Response to Acute Long-term Submaximal Exercise in Sedentary Men

Introduction: Exercise training increases skeletal muscle capillary density, but the molecular mechanisms of this process are not yet clear. The aim of the present study was to investigate the effect of acute long- term submaximal exercise on serum vascular endothelial growth factor (VEGF) as the main angiogenic factor, and matrix metalloproteinases 2 and 9 ( MMP-2 and MMP-9), as the degrading factors of basement membrane in sedentary men. Methods: Twelve healthy sedentary men (mean age ± SD = 22.37 ± 2.30 years mean BMI ± SD 23.91 ± 2.74) were randomly selected among the volunteers. After determining VO2 max, subjects exercised on ergometer for 1 h at 70% V02 max. Two ml of blood was taken from antecubital vein immediately after exercise and 2 hours postexercise. Serum VEGF, MMP-2 and MMP-9 were measured by ELISA. Results: Serum levels of VEGF and MMP-2 decreased immediately after exercise. Two hours after exercise, the serum VEGF remained at a lower level but serum MMP-2 returned to basal level. No change was detected in the serum levels of MMP-9 immediately and 2 h after exercise. Conclusion: Acute submaximal exercise decreased the main factors involved in the development of capillary network in sedentary men. This might be due to the fact that the submaximal exercise could not provide the two main stimulating factors of angiogenesis, i.e. shear stress and hypoxia. It could also be explained by the fact that the mechanism of development of capillary network following regular exercise training is different from that following an acute exercise.