Diesel exhaust inhalation enhances airway hyperresponsiveness in mice.
BACKGROUND
Repeated intratracheal instillation of diesel exhaust particles and ovalbumin-induced airway hyperresponsiveness and airway inflammation in mice. However, the effects of daily inhalation of diesel exhaust may differ from the effects of direct instillation.


METHODS
Therefore, mice were exposed to diesel exhaust by inhalation 12 h per day for 3 months. Before the diesel exhaust exposure, ovalbumin was injected intraperitoneally as a sensitization. After 3 weeks of diesel exhaust exposure, these mice were challenged with ovalbumin every 3 week thereafter.


RESULTS
Diesel exhaust exposure with antigen challenge induced airway hyperresponsiveness and airway inflammation which was characterized by increased numbers of eosinophils and mast cells in lung tissue. The recruitment of inflammatory cells was accompanied by an increment in goblet cells on bronchial epithelium. Diesel exhaust exposure alone also enhanced airway hyperresponsiveness, but did not induce eosinophilic infiltration and/or an increment in goblet cells.


CONCLUSIONS
Diesel exhaust inhalation enhanced airway hyperresponsiveness and airway inflammation caused by ovalbumin sensitization in mice.
Miyabara
Y
Y
Research Team for Health Effects of Air Pollutants, National Institute for Environmental Studies, Ibaraki, Japan. miyabara@nies.go.jp
Ichinose
T
T
Takano
H
H
Sagai
M
M
D000818:Animals; D016535:Bronchial Hyperreactivity / Q000209:etiology* / Q000503:physiopathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002465:Cell Movement; D004787:Environmental Pollution / Q000009:adverse effects; D004804:Eosinophils / Q000166:cytology; D000939:Epitopes; D006965:Hyperplasia / Q000473:pathology; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D019570:Inhalation Exposure / Q000009:adverse effects*; D007958:Leukocyte Count / Q000187:drug effects; D008168:Lung / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000166:cytology; D051379:Mice; D008809:Mice, Inbred C3H; D010047:Ovalbumin / Q000276:immunology; D001335:Vehicle Emissions / Q000009:adverse effects*
D000939:Epitopes; D007074:Immunoglobulin G; D001335:Vehicle Emissions; D007073:Immunoglobulin E; D010047:Ovalbumin