title: Accumulation of an endogenous inhibitor of nitric oxide synthesis and oxidative DNA damage in end-stage renal disease.
abstract: BACKGROUND
  Elevated oxidative status and reduced antioxidant defence systems in patients with chronic renal failure (CRF) accelerate the prevalence of atherosclerosis and other chronic complications. We aimed to investigate the levels of reactive oxygen, nitrogen species, and antioxidants in patients with end-stage renal disease (ESRD) having hemodialysis and controls and evaluate the factors that might influence the oxidative-antioxidative balance.
  
  
  METHODS
  Sixty four patients with ESRD were enrolled in this study. Twenty two controls with normal renal function were included. 8-hydroxy-2'-deoxyguanosine, asymmetric dimethylarginine, and nitrotyrosine levels were quantitated by Elisa. Catalase was assayed with a colorimetric method. Glutathione, nitric oxide, total antioxidant capacity, and lipid hydroperoxide were assayed spectrophotometrically.
  
  
  RESULTS
  8-hydroxy-2'-deoxyguanosine, asymmetric dimethylarginine, nitrotyrosine, and nitric oxide levels of patients were higher than those of the control group (p < 0.01) (p < 0.001), respectively. Total antioxidant capacity and catalase activity were significantly increased in controls compared to patients with renal failure (p < 0.001) (p < 0.01), respectively.
  
  
  CONCLUSIONS
  Our data confirmed the previous findings that an increase in oxidative stress may be considered as one of the major risk factors in CRF patients. The lowering of total antioxidant defences in patients with end-stage renal disease on hemodialysis may contribute to the increased oxidative damage and to the development of renal complications.
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Gazi University, Ankara, Turkey. abozkir@gazi.edu.tr
authors.forename: Aysun
authors.initials: A
authors.lastname: Hacişevki
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
authors.forename: Aymelek
authors.initials: A
authors.lastname: Gönenç
authors.affiliation: Department of Nephrology, Faculty of Medicine, Başkent University, Ankara, Turkey.
authors.forename: Siren
authors.initials: S
authors.lastname: Sezer
authors.affiliation: Department of Nephrology, Faculty of Medicine, Başkent University, Ankara, Turkey.
authors.forename: Sebnem
authors.initials: S
authors.lastname: Karakan
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
authors.forename: Bolkan
authors.initials: B
authors.lastname: Simşek
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
authors.forename: Meral
authors.initials: M
authors.lastname: Torun
mesh_terms: D016022:Case-Control Studies; D004249:DNA Damage; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005978:Glutathione / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D018384:Oxidative Stress
chemical_list: D009569:Nitric Oxide; D005978:Glutathione