title: [Effects of tyrosine oxidation products on redox state in myocardium of rats].
abstract: OBJECTIVE
  To explore the effects of tyrosine oxidized products (TOP) on the redox state of rats myocardium and investigate the oxidative damage mechanism.
  
  
  METHODS
  Male SD Rats were randomly assigned to three groups and treated respectively with normal diet (Group C), 440 mg/kg TOP (Group TOP), 440 mg/kg tyrosine oxidized products plus 5 mg/kg lipoic acid (Group TOP + LA). Indicators of oxidative stress in blood and myocardial were measured at the end of 6 weeks, 12 weeks and 24 weeks. RT-PCR was used to detect mRNA expression of Nrf2, Trx, NF-κB and AP-1 in myocardium.
  
  
  RESULTS
  Compared to the control group (Group C), reactive oxygen species (ROS), carbonyl (PC), malondialdehyde (MDA), dityrosine (Dityr), 3-nitrotyrosine (3-NT) in rats blood and myocardium were all significantly increased in the TOP group (P < 0.05). Total antioxidant capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), reducing glutathione (GSH) and oxidized glutathione (GSSG) levels all decreased significantly (P < 0.05). The mRNA expression of Nrf2, Trx-1, NF-κB, AP-1 RNA significantly up-regulated (P < 0.05) in the TOP group compared to the control.
  
  
  CONCLUSIONS
  Tyrosine oxidized products impairs antioxidant defense system and lead to accumulation of protein oxidation products in rats myocardium. Moreover, lipoic acid performs a positive effect in the protective reaction, which may adjusted by regulation of redox signaling pathway.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhao
authors.forename: Zhuqing
authors.initials: Z
authors.lastname: Li
authors.forename: Yingyi
authors.initials: Y
authors.lastname: Ding
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Shi
authors.forename: Guowei
authors.initials: G
authors.lastname: Le
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002374:Catalase; D005978:Glutathione; D005979:Glutathione Peroxidase; D006321:Heart / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde; D016328:NF-kappa B; D010084:Oxidation-Reduction / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D008063:Thioctic Acid; D018808:Transcription Factor AP-1; D014443:Tyrosine / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D018808:Transcription Factor AP-1; C002744:3-nitrotyrosine; D014443:Tyrosine; D008315:Malondialdehyde; D008063:Thioctic Acid; C007543:dityrosine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione