title: Altered antioxidant defense system in clinically stable patients with schizophrenia and their unaffected siblings.
abstract: OBJECTIVE
  To determine Red Blood Cell (RBC) antioxidant enzyme activities and plasma Thiobarbituric Acid Reactive Substances (TBARS) in clinically stable patients with schizophrenia and their unaffected siblings.
  
  
  METHODS
  A case-control study carried out on three groups: 60 schizophrenic patients treated with neuroleptics, 33 of their unaffected siblings and 30 healthy controls with no family psychiatric history. Biological markers were measured on fasting patients after a period of tobacco abstinence: RBC antioxidant enzyme activities - superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) - by spectrophotometry and plasma levels of TBARS by spectrofluorimetry.
  
  
  RESULTS
  RBC SOD and CAT activities were significantly lower in schizophrenic patients and their unaffected siblings compared to the control group (P<0.001). Schizophrenic patients also had significantly lower RBC GSH-Px activity than controls (P=0.03), whereas their unaffected siblings had significantly higher RBC GSH-Px activity than controls (P=0.04). Plasma TBARS were higher in schizophrenic patients than their unaffected siblings: 2.1+/-0.8 micromol/l vs. 1.7+/-0.6 micromol/l (P=0.06).
  
  
  CONCLUSIONS
  Our results showed a decrease in antioxidant enzyme activities and an increase in lipid peroxidation confirming the existence of oxidative stress in schizophrenic patients treated with neuroleptics. Additionally, this suggests that the increase in GSH-Px activity in unaffected siblings would be a protective mechanism against oxidative stress and damage. Other studies are necessary to confirm these findings.
authors.affiliation: Research Laboratory Trace Elements, Free Radicals and Antioxidants, Biophysics Department, Faculty of Medicine, 5000 Monastir, Tunisia.
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Othmen
authors.forename: Anwar
authors.initials: A
authors.lastname: Mechri
authors.forename: Chiraz
authors.initials: C
authors.lastname: Fendri
authors.forename: Muriel
authors.initials: M
authors.lastname: Bost
authors.forename: Guy
authors.initials: G
authors.lastname: Chazot
authors.forename: Lotfi
authors.initials: L
authors.lastname: Gaha
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Kerkeni
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002374:Catalase / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000097:blood* / Q000201:enzymology* / Q000235:genetics; D035781:Siblings; D013053:Spectrophotometry / Q000379:methods; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*