Three polymorphisms of the eNOS gene and plasma levels of metabolites of nitric oxide in depressed Japanese patients: A preliminary report

Background: Depression is a risk factor for coronary heart disease. Nitric oxide (NO) plays an important role in both coronary heart disease and depression. Methods: Fifty-one inpatients and outpatients who met the Diagnostic and Statistical Manual of Mental Disordersa-Fourth Edition criteria for major depressive disorder (MDD) in the university hospital of the University of Occupational and Environmental Health and 58 age-matched and sex-matched healthy controls enrolled in this study. We investigated the association between the three polymorphisms of the endothelial nitric oxide synthase (eNOS) gene (single-nucleotide polymorphism (SNP); rs2070744, rs1799983, variable number tandem repeat (VNTR) in intron 4) and scores on the Hamilton Rating Scale for Depression, plasma metabolites of NO (NO _x) or ankle brachial index in patients with MDD and healthy controls. Results: We did not find significant differences in the genotype distributions between patients with MDD and healthy volunteers. No associations were observed between any of the polymorphisms of the eNOS gene and the Hamilton Rating Scale for Depression or ankle brachial index in patients with MDD. However, plasma NO _x level was significantly associated with a polymorphism of the eNOS gene (rs207044 and variable number tandem repeat in intron 4). Conclusion: These results suggest that the direct association was not observed between the polymorphisms of the eNOS gene and the pathogenesis of depression.