title: Expression of ENaC in LPS-induced inflammation of middle ear mucosa.
abstract: CONCLUSIONS
  The expression of all three subunits of the epithelial sodium channel (ENaC) decreased after the lipopolysaccharide (LPS) injection and normalized as the fluid collection resolved. This implies that fluid collection in acute otitis media may be caused by the inhibition of ENaC function.
  
  
  OBJECTIVE
  We investigated the expression levels of subunits of ENaC after an injection of LPS into the middle ear cavity of rats.
  
  
  METHODS
  Seventy-two Sprague-Dawley rats were assigned randomly into the five groups that received an LPS injection and the control group. A transtympanic injection of LPS (1 mg/ml) was done and rats were sacrificed 6, 12, 24, 72, and 120 h after the procedure. Real-time RT-PCR was carried out for ENaC-α, -β, -γ, and immunohistochemistry was performed for ENaC-α and -β.
  
  
  RESULTS
  The level of ENaC-α expression decreased 0.50-fold and 0.55-fold at 6 and 12 h, respectively (p < 0.05), but it normalized at 24 h. It increased 3.64-fold at 72 h and 3.24-fold at 120 h (p < 0.05). At 6 and 12 h after the LPS injection into the middle ear cavity, inflammation was induced and ENaC-α immunoreactivity decreased. At 24 h, ENaC-α immunoreactivity was normalized, then at 72 and 120 h after the injection it was increased.
authors: Department of Otorhinolaryngology-Head and Neck Surgery, Dongguk University Ilsan Hospital, Korea.
authors: Jae-Jun
authors: JJ
authors: Song
authors: Seong Keun
authors: SK
authors: Kwon
authors: Chang Gun
authors: CG
authors: Cho
authors: Seok-Won
authors: SW
authors: Park
authors: Sung-Won
authors: SW
authors: Chae
mesh_terms: D000818:Animals; D053503:Epithelial Sodium Channels / Q000378:metabolism*; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism / Q000473:pathology*; D008070:Lipopolysaccharides; D008297:Male; D009092:Mucous Membrane / Q000378:metabolism; D010033:Otitis Media / Q000209:etiology* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D053503:Epithelial Sodium Channels; D008070:Lipopolysaccharides; D012333:RNA, Messenger