The effects of regular aerobic exercise on blood nitric oxide and endothelial nitric oxide synthase protein levels and the role of endothelial nitric oxide synthase intron 4A/B polymorphism

The effects of regular aerobic exercise on blood nitric oxide and endothelial nitric oxide synthase protein levels and the role of endothelial nitric oxide synthase intron 4a/b polymorphism Introduction: Nitric oxide (NO), endothelial nitric oxide synthase protein (eNOS) levels and eNOS intron 4a / b polymorphism are risk factors for coronary artery diseases. Effects of aerobic exercise on NO and eNOS and the role of eNOS intron 4a/b polymorphism is unclear. The aim of this study is to investigate the effect of regular aerobic exercise on blood NO, endothelial nitric oxide synthase protein (eNOS) level and the role of eNOS intron 4a / b polymorphism. Methods: 46 well trained male soccer refree as athletic group (AG; 23,3±2,84 age) and 43 sedantery male as control group (CG; 23,2±3,28 age) participated in this study. Post prandial blood examples is used to determine NO, eNOS and oxidized LDL (OxLDL) levels measured by ELISA and total antioxidant / oxidant status (TAS / TOS ), thiobarbituric acid reactive substances (TBARS) levels determined by spectrophotometrically. eNOS intron 4a / b polymorphism was determined by PCR-RFLP and VNTR method from genomic DNA samples taken from peripheral blood. Serum lipid and lipoprotein levels and aspartate aminotransferase (AST) and alanine amino transferase (ALT) enzyme activities were determined by standard enzymatic-kinetic methods in an autoanalyzer. Results: When polymorphism is not considered; no significant difference is found between AG and CG for NO, eNOS, TOS, TBARS, total cholesterol (TC), triglyceride (TG), high and low density lipoprotein cholesterol (HDL-C and LDL-C) levels. However, the OxLDL and oksidative stress index (OSI; TOS/TAS ration ) levels of the athletes group are significantly lower than the control group (p = 0.011) whereas TAS level is greater (p = 0,000). When athletic and control genotype groups considered; there was no difference for NO and eNOS between the carrier group (Ac = aa+ab,) and the b homozygous group (bb), and the role of polymorphism is not found on the results. In control genotype group, the eNOS value of the aT genotype group was found to be greater than the bb group. In addition, NO (26%), AST (86%) and ALT (23%) values of the bb genotype group in the control group were greater than the aT carrier group (p>0.05). In athletic group, NO (29%) values of the homozygote bb group were higher than the aT group. In addition, TBARS (18%), TOS (16%) and AST (18%) values of the aT group in the athletic group were greater than the homozygote bb group. Conclusions: These findings suggest that regular aerobic exercise increased antioxidant capacity and decreased the level of OksLDL, however, this exercise does not have a significant effect on blood NO and eNOS levels, but also shows that eNOS intron 4a / b polymorphism has no significant role on these results. The differences between serum eNOS and NO values in control genotype groups may have been due to the mentioned polymorphism. In addition, it maybe said that the aerobic training has no significant effect on blood lipid and lipoprotein levels. Keywords: Aerobic exercise; endothelial nitric oxide intron 4a/b polymorphism; nitric oxide; oxidative stress; soccer refree