title: Effects of chronic intermittent hypoxia on genioglossus in rats.
abstract: OBJECTIVE
  The objective of this study was to investigate the effects of chronic intermittent hypoxia (CIH) on genioglossal ultrastructure and mitochondrial function as well as the intervention role of adiponectin (Ad).
  
  
  METHODS
  Forty-two Wistar rats were randomly divided into three groups with 14 rats in each. Rats in group A were kept breathing normal air, while rats in both groups B and C received the same CIH environment (a 2-min cycle, 1 min on, 1 min off with a nadir O(2) at 4-5%, 8 h/day for successive 5 weeks). However, rats in group C was given regular intravenous Ad injection (10 μg per time, twice a week for successive 5 weeks). A simultaneous intravenous injection of saline (0.5 ml per time) was carried in groups A and B. At the end of experiment, the genioglossal ultrastructure, the serum adiponectin levels, the mitochondrial membrane potential (ΔΨ(m)), and activities of respiratory chain complexes I and IV in mitochondrion of genioglossal cells were compared among groups.
  
  
  RESULTS
  Serum Ad level was significantly lower in group B than that in group A (P < 0.01). In group B, there were genioglussal myofibril discontinuities, lysis of myofilament, edema of mitochondria, and disruption of cristae, vacuolus, and lysis of some mitochondria. These pathological changes were less significant in group C. The relative value of ΔΨ(m) was the lowest in group B but the highest in group A (P < 0.01), with group B in between. The concentrations of mitochondrial complexes I and IV in group B were the lowest but became higher and higher from group C to A, with a significant difference among groups (all P < 0.05).
  
  
  CONCLUSIONS
  CIH could lead to hypoadiponectinemia, impaired genioglossal ultrastructure, and mitochondrial dysfunction. These changes could be improved by supplement of Ad.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
authors.forename: Hanpeng
authors.initials: H
authors.lastname: Huang
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhang
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Yin
authors.initials: Y
authors.lastname: Min
authors.forename: Xilong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D052242:Adiponectin / Q000097:blood; D000818:Animals; D042967:Electron Transport Complex I / Q000008:administration & dosage / Q000097:blood*; D003576:Electron Transport Complex IV / Q000097:blood*; D004734:Energy Metabolism / Q000502:physiology; D005434:Flow Cytometry; D000860:Hypoxia / Q000473:pathology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D046529:Microscopy, Electron, Transmission; D008931:Mitochondria, Muscle / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D014059:Tongue / Q000473:pathology*
chemical_list: D052242:Adiponectin; D003576:Electron Transport Complex IV; D042967:Electron Transport Complex I