title: Effect of recombinant vascular endothelial growth factor on experimental otitis media with effusion.
abstract: CONCLUSIONS
  This study demonstrates that rVEGF in the middle ear cavity contributes significantly to the development of OME by increasing the vascular permeability of the middle ear mucosa.
  
  
  OBJECTIVE
  Vascular endothelial growth factor (VEGF) has been detected in otitis media with effusion (OME). It has a very strong effect on increasing vascular permeability, and is much more potent than platelet-activating factor, arachidonic acid metabolites or histamine. The purpose of this study was to investigate whether recombinant VEGF (rVEGF) can increase vascular permeability in the middle ear mucosa of rats.
  
  
  METHODS
  rVEGF was injected transtympanically at doses of 0.01, 0.1 and 1.0 microg in the experimental groups; normal saline was injected in the control group. Twenty-four h after the injection of rVEGF, middle ear fluid was aspirated and the vascular permeability of the middle ear mucosa was measured by means of the Evans Blue vital dye technique.
  
  
  RESULTS
  Extravasation of Evans Blue dye was found in all specimens injected with rVEGF, and was quantified using a spectrophotometer. Middle ear fluid developed in all ears injected with 0.1 or 1.0 microg of rVEGF and histopathology of the middle ear mucosa revealed severe inflammatory cellular infiltration, subepithelial edema and vascular dilatation. Rats injected with 1.0 microg of rVEGF showed a significant increase in middle ear vascular permeability in comparison with the control group (p < 0.05).
authors.affiliation: Department of Otolaryngology--Head and Neck Surgery, Korea University College of Medicine, Sungbuk-Ku, Seoul, South Korea.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Kim
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Chae
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hak Hyun
authors.initials: HH
authors.lastname: Jung
mesh_terms: D000818:Animals; D002199:Capillary Permeability; D004396:Coloring Agents; D004432:Ear, Middle / Q000378:metabolism / Q000473:pathology; D005070:Evans Blue; D005119:Extravasation of Diagnostic and Therapeutic Materials; D009092:Mucous Membrane / Q000378:metabolism; D010034:Otitis Media with Effusion / Q000209:etiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000493:pharmacokinetics*; D042461:Vascular Endothelial Growth Factor A / Q000493:pharmacokinetics*; D014664:Vasodilation / Q000187:drug effects
chemical_list: D004396:Coloring Agents; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D005070:Evans Blue