title: Genistein attenuates genioglossus muscle fatigue under chronic intermittent hypoxia by down-regulation of oxidative stress level and up-regulation of antioxidant enzyme activity through ERK1/2 signaling pathway.
abstract: OBJECTIVE
  This study aims to investigate the effects of genistein on contractile properties of genioglossus under chronic intermittent hypoxia (CIH) conditions and its relationship with oxidative stress, antioxidant enzyme, and ERK1/2 signaling pathway.
  
  
  METHODS
  Fifty female Sprague-Dawley rats were randomly divided into five groups 1 week after ovariectomy: the normal control group, the CIH group, the CIH with low-dose, medium-dose, and high-dose genistein groups. Rats in the latter four groups were exposed to CIH for 5 weeks. Twitch tension, tetanic tension, and fatigue resistance of genioglossus were investigated. Malondialdehyde (MDA) and mitochondrial reactive oxygen species (ROS), enzymatic activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and ERK1/2 were detected.
  
  
  RESULTS
  Muscle fatigue resistance and enzymatic activity of GPx, CAT, and SOD were reduced after CIH exposure and improved by different doses of genistein at different degrees. CIH increased the level of ROS and MDA, and they were returned to normal by genistein. The expression of phospho-ERK1/2 is opposite to the changes in muscle fatigue resistance.
  
  
  CONCLUSIONS
  Chronic intermittent hypoxia decreases fatigue resistance of genioglossus, and genistein treatment reverses the fatigability of genioglossus by down-regulation of oxidative stress level and up-regulation of antioxidant enzymatic activity probably through ERK1/2 signaling pathway.
authors: Department of Orthodontics, School of Stomatology, Tongji University, Shanghai, China.
authors: Wh
authors: W
authors: Ding
authors: Yh
authors: Y
authors: Liu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002374:Catalase / Q000032:analysis / Q000187:drug effects; D015536:Down-Regulation; D005152:Facial Muscles / Q000187:drug effects*; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000032:analysis / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology*; D007537:Isometric Contraction / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008315:Malondialdehyde / Q000032:analysis; D008931:Mitochondria, Muscle / Q000187:drug effects; D018763:Muscle Fatigue / Q000187:drug effects*; D009129:Muscle Tonus / Q000187:drug effects; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000187:drug effects*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000032:analysis; D013482:Superoxide Dismutase / Q000032:analysis / Q000187:drug effects; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D019833:Genistein; D010088:Oxidoreductases; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase