title: Adiponectin alleviates contractile dysfunction of genioglossus in rats exposed to chronic intermittent hypoxia.
abstract: BACKGROUND
  Genioglossal dysfuntion takes an important role in pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS) in which chronic intermittent hypoxia (CIH) is the major pathological origin. Recent studies have suggested genioglossal injury induced by CIH might be improved by adiponectin. The aim of this study was to investigate the effects of adiponectin on genioglossus contractile properties in rats exposed to CIH.
  
  
  METHODS
  Thirty-nine healthy male Wistar rats were randomly divided into three groups: normal control (NC), CIH and adiponectin supplement (CIH+Ad) with 13 rats in each. Rats in NC were kept breathing normal air, while rats in CIH and CIH+Ad experienced the same CIH environment eight hours per day for 35 successive days. Rats in CIH+Ad were given intravenous adiponectin of 10 µg twice a week for 30 successive days. Rats in the NC and CIH were injected with normal saline as a control. After 35 days' CIH exposure, the levels of serum adiponectin and genioglossus contractile properties were compared.
  
  
  RESULTS
  Serum adiponectin level was significantly lower in CIH than in NC (1210 ng/ml vs. 2236 ng/ml). Serum adiponectin level in CIH+Ad (1844 ng/ml) was significantly higher than CIH but lower than NC. Twitch tension, time to peak tension, half relaxation time and tetanic tension were significantly lower in CIH than NC and improved in CIH+Ad. All mean tetanic fatigue indices decreased more rapidly in the first 20 seconds than during the subsequent 100 seconds. Tetanic fatigue indices in NC and CIH+Ad were significantly higher compared to CIH.
  
  
  CONCLUSIONS
  CIH could lead to hypoadiponectinaemia, impaired genioglossus contractile properties and decreased fatigue resistance in rats. Such changes could be partially offset by supplementation of adiponectin.
authors.affiliation: Department of Respiratory Medicine, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210001, China.
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Wang
authors.forename: Gan
authors.initials: G
authors.lastname: Lu
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.forename: Han-Peng
authors.initials: HP
authors.lastname: Huang
authors.forename: Wen-Xiao
authors.initials: WX
authors.lastname: Ding
authors.forename: Xi-Long
authors.initials: XL
authors.lastname: Zhang
mesh_terms: D052242:Adiponectin / Q000097:blood* / Q000627:therapeutic use; D000818:Animals; D000860:Hypoxia / Q000097:blood* / Q000503:physiopathology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology
chemical_list: D052242:Adiponectin