title: Evaluation of nitrite/nitrate levels in relation to oxidative stress parameters in liver cirrhosis.
abstract: OBJECTIVE
  Nitric oxide and reactive oxygen species have been implicated in several pathophysiological events leading to fibrosis and cirrhosis. The aim of the present study was to investigate the possible contribution of peroxynitrite (formed by the interaction of nitric oxide and superoxide anion) in the pathophysiology of cirrhosis.
  
  
  METHODS
  Twenty-six cirrhotic patients classified as Child-Pugh A, and seven as Child-Pugh B, were included in the study, and nine healthy volunteers served as controls. Levels of nitrite/nitrate (NOx), thiobarbituric acid-reactive substances (TBARS), nitrotyrosine (peroxynitrite marker), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) were measured in blood samples.
  
  
  RESULTS
  NOx, TBARS, CAT, SOD and GSH levels were higher in cirrhosis patients than in the controls (NOx: 0.17 ± 0.02, 0.95 ± 0.12, 1.3 ± 0.1; TBARS: 2.0 ± 0.05, 4.6 ± 0.3, 5 ± 0.3; CAT: 1.8 ± 0.1, 4 ± 0.3, 4.5 ± 0.4; SOD: 1.8 ± 0.2, 4.8 ± 0.5, 7 ± 0.4; and GSH: 1.3 ± 0.05, 3.6 ± 0.3, 4.5 ± 0.6 in controls, and Child-Pugh A and B patients, respectively). However, there were no differences in nitrotyrosine levels across these groups (controls: 11.4 ± 0.4; Child-Pugh A: 11.1 ± 0.4; Child-Pugh B: 11.9 ± 1.6). NOx levels showed significant and strongly positive correlations with TBARS, SOD, CAT and GSH levels. In contrast, no correlations were found between either NOx or TBARS and nitrotyrosine levels.
  
  
  CONCLUSIONS
  Nitric oxide and reactive oxygen species, but not peroxynitrite, are overproduced in patients with cirrhosis in spite of evidence of an increase in antioxidant defenses. This suggests that therapeutic measures aimed at attenuating oxidative stress as well as increasing antioxidant defenses may well benefit patients with cirrhosis.
authors.affiliation: Department of pharmacology, School of Medicine, Kahramanmaraş Sütçü İmam University, Kahramanmaraş, Turkey. yusufergun@ksu.edu.tr
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Ergün
authors.forename: Ergül Belge
authors.initials: EB
authors.lastname: Kurutaş
authors.forename: Burhan
authors.initials: B
authors.lastname: Ozdil
authors.forename: Ramazan
authors.initials: R
authors.lastname: Güneşaçar
authors.forename: Yılmaz
authors.initials: Y
authors.lastname: Ergün
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D006801:Humans; D008103:Liver Cirrhosis / Q000378:metabolism*; D008875:Middle Aged; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D018384:Oxidative Stress
chemical_list: D009566:Nitrates; D009573:Nitrites