title: Systemic oxidative stress in children and teenagers with Down syndrome.
abstract: OBJECTIVE
  The aim of this study was to evaluate the antioxidant status and oxidative stress biomarkers in the blood of children and teenagers with Down syndrome.
  
  
  METHODS
  The analysis of enzymatic antioxidant defenses, such as the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione transferase (GST), non-enzymatic antioxidants, such as levels of reduced glutathione (GSH), uric acid (UA) and vitamin E, as well as oxidative damage indicators, such as protein carbonyls (PC) levels and lipoperoxidation (TBARS), of DS individuals (n=20) compared to healthy controls (n=18). Except the vitamin E was measured by HPLC, all other markers were measured spectrophotometrically.
  
  
  RESULTS
  Antioxidant enzymes analysis showed significant increases in the SOD (47.2%), CAT (24.7%) and GR (49.6%) activities in DS subjects. No significant difference in GPx activity was detected while GST activity (61.2%) was decreased, and both responses may be consequence of the depletion of GSH (24.9%) levels. There were no significant differences in TBARS levels, while PC levels showed decreased (31.7%) levels compared to healthy controls, which may be related to the increase (16.1%) found in serum UA. Levels of vitamin E showed no significant differences between DS individuals compared to controls.
  
  
  CONCLUSIONS
  The results revealed a systemic pro-oxidant status in DS individuals, evidenced by the increased activity of some important antioxidant enzymes, together with decreased GSH levels in whole blood and elevated UA levels in plasma, probably as an antioxidant compensation related to the redox imbalance in DS individuals.
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
authors.forename: Thais Regina
authors.initials: TR
authors.lastname: Garlet
authors.forename: Eduardo Benedetti
authors.initials: EB
authors.lastname: Parisotto
authors.forename: Guilherme da Silva
authors.initials: Gda S
authors.lastname: de Medeiros
authors.forename: Letícia Cristina Radin
authors.initials: LC
authors.lastname: Pereira
authors.forename: Emilia Ad Dison Machado
authors.initials: EA
authors.lastname: Moreira
authors.forename: Eduardo Monguilhott
authors.initials: EM
authors.lastname: Dalmarco
authors.forename: Juliana Bastos
authors.initials: JB
authors.lastname: Dalmarco
authors.forename: Danilo
authors.initials: D
authors.lastname: Wilhelm Filho
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D050050:Protein Carbonylation; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*; D014527:Uric Acid / Q000097:blood; D014810:Vitamin E / Q000097:blood*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D014527:Uric Acid
keywords: Antioxidants; Down syndrome; Oxidative stress; Reactive oxygen species