title: Influence of Hemodialysis on Lipid Peroxidation, Enzymatic and Non-Enzymatic Antioxidant Capacity in Chronic Renal Failure Patients.
abstract: BACKGROUND
  Free radical induced damages are thought to be involved in chronic kidney disease (CKD), especially in patients who are on hemodialysis (HD) for prolonged periods. Hemodialysis can influence multiple biochemical factors, several of which are useful, although the rest can be harmful and increase the severity of disease.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the effect of the HD membrane polysulfone on oxidative stress markers, by measuring the level of lipid peroxidation and total antioxidant activity (TAC), in the blood of HD patients.
  
  
  METHODS
  This study was carried out on 31 HD patients and 31 healthy persons, matched for age and sex, as control group. Blood samples were drawn before and after HD from arteriovenous fistulas, and once from the controls. Superoxide dismutase (SOD), catalase (CAT) and thiobarbituric acid-reactive substance (TBARS) in blood hemolyzate, Glutathione peroxidase (GpX) of whole blood and TAC of plasma were measured, respectively. Then, we investigated the association between TAC of plasma, measured by ferric reducing antioxidant power (FRAP), and lipid peroxidation level with its related parameters, in HD patients.
  
  
  RESULTS
  The SOD, GpX and CAT were decreased after HD (P < 0.05). Also, FRAP was shown to decrease after HD (P < 0.05). However, erythrocyte TBARS levels (μmol/gr of Hb) were increased after HD, in comparison with controls, and before HD (P < 0.05). There was a significant negative correlation between TBARS and antioxidant indices, such as SOD (r = -0.67, P = 0.001), GpX (r = -0.76, P = 0.001), CAT (r = -0.63, P = 0.001) and FRAP (r = -0.84, P = 0.001). The FRAP was significantly and directly correlated with uric acid (r = +0.62, P = 0.001), SOD (r = +0.72, P = 0.001), GpX (r = +0.87, P = 0.001) and CAT (r = +0.84, P = 0.001).
  
  
  CONCLUSIONS
  The results of our study proposed that there is a loss or inactivation of antioxidant factors, coupled with increased lipid peroxidation during the procedure of HD, possibly through the dialyzer membrane, with probable consequences on the severity of illness.
authors.affiliation: Department of Biochemistry, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari,IR Iran.
authors.forename: Mehryar
authors.initials: M
authors.lastname: Zargari
authors.affiliation: Department of Nephrology, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors.forename: Omid
authors.initials: O
authors.lastname: Sedighi
keywords: Catalase; Glutathione Peroxidase; Lipid Peroxidation; Renal Dialysis; Superoxide Dismutase; Uric Acid