Reversible and irreversible airway inflammation and fibrosis in mice exposed to inhaled ovalbumin.
OBJECTIVE
We examined the reversibility of several changes in the lungs and airways of mice immediately after exposure to ovalbumin aerosol and after a period of recovery breathing clean air.


METHODS
Mice were exposed for 1, 2, 4, 6, 8, or 10 weeks, with recovery in clean air for 1-3 weeks.


RESULTS
Airway collagen content, exhaled NO, airway mucous cell hyperplasia, and lung lavage inflammatory cell content increased upon exposure to ovalbumin aerosol. All parameters except airway fibrosis decreased partially or completely to control values with recovery in clean air.


CONCLUSIONS
Airway mucous cell hypertrophy and hyperplasia appear to be completely reversible after recovery in clean air, while exhaled NO and airway inflammation appear to be mostly reversible, except for persistence of lymphocytes in the lung lavage fluid. Airway fibrosis appears to be reversible when mice are exposed to ovalbumin aerosol for periods of up to 4 weeks of exposure, but becomes irreversible after 6 or more weeks of exposure.
Kenyon
N J
NJ
Pulmonary/Critical Care Medicine, School of Medicine, University of California, Davis, CA, 95616, USA.
Last
J A
JA
D000280:Administration, Inhalation; D000818:Animals; D001982:Bronchial Diseases / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D001991:Bronchitis / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D003094:Collagen / Q000378:metabolism; D004334:Drug Administration Schedule; D045853:Exhalation; D005260:Female; D005355:Fibrosis; D006965:Hyperplasia; D006984:Hypertrophy; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide; D010047:Ovalbumin / Q000008:administration & dosage*; D011014:Pneumonia / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D020545:Respiratory Mucosa / Q000378:metabolism / Q000473:pathology
D009569:Nitric Oxide; D010047:Ovalbumin; D003094:Collagen