title: Changes in expression profiles of antioxidant enzymes in diabetic rat kidneys.
abstract: BACKGROUND
  In diabetes mellitus, increased formation of reactive oxygen species due to high level of glucose in both blood plasma and tissues creates oxidative stress and damages the tissues. Antioxidants together with the antioxidant enzymes are very important in order to protect the cells against oxidative damage.
  
  
  METHODS
  Differential expressions of both mRNA and proteins of major antioxidant enzymes in streptozotocin-induced diabetic rat kidneys were measured with the help of real-time polymerase chain reaction and western blot analysis, respectively. Furthermore, effects of two strong antioxidants α-lipoic acid, vitamin C and their combination on the regulation of both expressions and the activities of antioxidant enzymes were also studied.
  
  
  RESULTS
  In diabetic rat kidney tissue, both catalase and glutathione peroxidase activities were reduced (although mRNA expression for both was greatly increased) when compared with controls. No significant change was observed in superoxide dismutase (SOD) activity. Alpha-lipoic acid increased catalase activity towards the control values. Combined administration of alpha-lipoic acid and vitamin C increased the activities of both catalase and SOD, demonstrating a posttranslational effect. Glutathione concentrations were decreased in diabetic kidney; alpha-lipoic acid treatment partially restored the glutathione levels.
  
  
  CONCLUSIONS
  All data showed the importance of post-transcriptional and translational regulation of the antioxidant enzyme activities against oxidative stress that is associated with diabetes.
authors: Department of Biology, Karamanoğlu Mehmetbey University, Karaman, Turkey. sadi@kmu.edu.tr
authors: Gökhan
authors: G
authors: Sadi
authors: Nihan
authors: N
authors: Eryilmaz
authors: Egemen
authors: E
authors: Tütüncüoğlu
authors: Şahika
authors: Ş
authors: Cingir
authors: Tülin
authors: T
authors: Güray
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D004338:Drug Combinations; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D008297:Male; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D008063:Thioctic Acid / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D004338:Drug Combinations; D012333:RNA, Messenger; D008063:Thioctic Acid; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid