title: Continuous positive airway pressure (CPAP) induces early nasal inflammation.
abstract: OBJECTIVE
  To assess whether noninvasive application of nCPAP is a mechanical stimulus inducing early nasal inflammation.
  
  
  METHODS
  Prospective controlled animal study.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  32 male Sprague-Dawley rats (250-300 g).
  
  
  METHODS
  The rats were anesthetized and subjected to nCPAP=10 cm H2O and sham-CPAP through a mask for 3 h and 5 h (n=8 each).
  
  
  RESULTS
  After nCPAP or sham, nasal scraping was carried out to detect neutrophils, and septum and dorsal nasal concha were excised to assess gene expression of inflammatory markers by real time PCR. Percentage of neutrophils in nucleated cells in the nasal scrapings was significantly (P = 0.006) higher after 5 h of nCPAP (3.51% +/- 0.73%; m +/- SEM) than in the sham group (1.12% +/- 0.39%). When compared with sham, the mRNA of macrophage inflammatory protein-2 (MIP-2) in nasal tissue was significantly overexpressed after both 3 h (2.28-fold +/- 0.43-fold; P = 0.034) and 5 h (5.56-fold +/-1.88-fold; P = 0.002) of nCPAP=10 cm H2O. No significant changes were found in the gene expressions of tumor necrosis factor-alpha, nerve growth factor and tachykinin-1 receptor.
  
  
  CONCLUSIONS
  The compression applied by nCPAP (10 cm H2O, 5 h) on the nasal wall of healthy rats is a mechanical stimulus that triggers an early inflammatory process mediated by MIP-2, resulting in neutrophil extravasation.
authors.affiliation: Unitat de Biofisica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona - IDIBAPS, Barcelona, Spain.
authors.forename: Isaac
authors.initials: I
authors.lastname: Almendros
authors.forename: Irene
authors.initials: I
authors.lastname: Acerbi
authors.forename: Isabel
authors.initials: I
authors.lastname: Vilaseca
authors.forename: Josep M
authors.initials: JM
authors.lastname: Montserrat
authors.forename: Daniel
authors.initials: D
authors.lastname: Navajas
authors.forename: Ramon
authors.initials: R
authors.lastname: Farré
mesh_terms: D000818:Animals; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects*; D004195:Disease Models, Animal; D009296:Nasal Cavity / Q000276:immunology*; D020932:Nerve Growth Factor / Q000032:analysis; D009504:Neutrophils / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000032:analysis; D012220:Rhinitis / Q000209:etiology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D018040:Receptors, Neurokinin-1; D014409:Tumor Necrosis Factor-alpha; D020932:Nerve Growth Factor