Continuous positive airway pressure (CPAP) induces early nasal inflammation.
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.
Almendros
Isaac
I
Unitat de Biofisica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona - IDIBAPS, Barcelona, Spain.
Acerbi
Irene
I
Vilaseca
Isabel
I
Montserrat
Josep M
JM
Navajas
Daniel
D
Farré
Ramon
R
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
D018040:Receptors, Neurokinin-1; D014409:Tumor Necrosis Factor-alpha; D020932:Nerve Growth Factor