title: Plasma and erythrocyte glutathione peroxidase activity, serum selenium concentration, and plasma total antioxidant capacity in cats with IRIS stages I-IV chronic kidney disease.
abstract: BACKGROUND
  Serum selenium concentrations and the activity of plasma glutathione peroxidase (GPx) decrease with the progression of chronic kidney disease (CKD) in human patients. Selenium is considered a limiting factor for plasma GPx synthesis. Plasma total antioxidant capacity (TAC) is decreased in CKD cats in comparison to healthy cats.
  
  
  OBJECTIVE
  Serum selenium concentrations and plasma and erythrocyte GPx activity in cats with CKD are lower than in healthy cats. Serum selenium concentrations, the activity of enzymes, and plasma TAC progressively decrease with the progression of kidney disease according to IRIS (International Renal Interest Society) classification.
  
  
  METHODS
  Twenty-six client-owned cats in IRIS stages I-IV of CKD were compared with 19 client-owned healthy cats.
  
  
  METHODS
  A CBC, serum biochemical profile, urinalysis, plasma and erythrocyte GPx activity, serum selenium concentration, and plasma TAC were measured in each cat.
  
  
  RESULTS
  Cats in IRIS stage IV CKD had a significantly higher (P = .025) activity of plasma GPx (23.44 ± 6.28 U/mL) than cats in the control group (17.51 ± 3.75 U/mL). There were no significant differences in erythrocyte GPx, serum selenium concentration, and plasma TAC, either among IRIS stages I-IV CKD cats or between CKD cats and healthy cats.
  
  
  CONCLUSIONS
  Erythrocyte GPx activity, serum selenium concentration, and plasma TAC do not change in CKD cats compared with healthy cats. Selenium is not a limiting factor in feline CKD. Increased plasma GPx activity in cats with stage IV CKD suggests induction of antioxidant defense mechanisms. Antioxidant defense systems might not be exhausted in CKD in cats.
authors.affiliation: Clinic for Surgery and Small Animal Medicine, University of Ljubljana, Veterinary Faculty, Ljubljana, Slovenia.
authors.forename: M
authors.initials: M
authors.lastname: Krofič Žel
authors.forename: N
authors.initials: N
authors.lastname: Tozon
authors.forename: A
authors.initials: A
authors.lastname: Nemec Svete
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000201:enzymology / Q000378:metabolism*; D002415:Cats; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D010949:Plasma / Q000201:enzymology; D051436:Renal Insufficiency, Chronic / Q000201:enzymology / Q000378:metabolism / Q000662:veterinary*; D012643:Selenium / Q000097:blood*
chemical_list: D005979:Glutathione Peroxidase; D012643:Selenium
keywords: Antioxidants; Cats; Oxidative stress; Renal failure