title: Effects of dietary cysteine on blood sulfur amino acid, glutathione, and malondialdehyde concentrations in cats.
abstract: OBJECTIVE
  To determine effects of dietary cysteine on blood sulfur amino acids (SAA), reduced glutathione (GSH), oxidized glutathione (GSSG), and malondialdehyde (MDA) concentrations in cats.
  
  
  METHODS
  12 healthy adult cats.
  
  
  METHODS
  Cats were fed diets with a nominal (0.50 g/100 g dry matter [DM]), moderate (1.00 g/100 g DM), or high (1.50 g/100 g DM) cysteine content in a 3 X 3 Latin square design with blocks of 8 weeks' duration. Venous blood samples were collected after each diet had been fed for 4 and 8 weeks, and a CBC and serum biochemical analyses were performed; poikilocyte, reticulocyte, and Heinz body counts were determined; and MDA, GSH, GSSG, and SAA concentrations were measured.
  
  
  RESULTS
  Blood cysteine and MDA concentrations were not significantly affected by dietary cysteine content. Blood methionine, homocysteine, and GSSG concentrations were significantly increased when cats consumed the high cysteine content diet but not when they consumed the moderate cysteine content diet, compared with concentrations obtained when cats consumed the nominal cysteine content diet. Blood GSH concentrations were significantly increased when cats consumed the moderate or high cysteine content diet.
  
  
  CONCLUSIONS
  Increased dietary cysteine content promotes higher blood methionine, homocysteine, GSH, and GSSG concentrations in healthy cats.
  
  
  CONCLUSIONS
  Supplemental dietary cysteine may be indicated to promote glutathione synthesis and ameliorate adverse effects of oxidative damage induced by disease or drugs.
authors: Department of Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523-1671, USA.
authors: M J
authors: MJ
authors: Fettman
authors: K D
authors: KD
authors: Valerius
authors: G K
authors: GK
authors: Ogilvie
authors: C L
authors: CL
authors: Bedwell
authors: K L
authors: KL
authors: Richardson
authors: J A
authors: JA
authors: Walton
authors: D W
authors: DW
authors: Hamar
mesh_terms: D000596:Amino Acids / Q000097:blood*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002415:Cats / Q000097:blood*; D003422:Critical Care; D003545:Cysteine / Q000494:pharmacology*; D019587:Dietary Supplements; D005260:Female; D005978:Glutathione / Q000097:blood*; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D018384:Oxidative Stress; D013455:Sulfur / Q000097:blood*
chemical_list: D000596:Amino Acids; D008315:Malondialdehyde; D013455:Sulfur; D005978:Glutathione; D003545:Cysteine