Neutrophil depletion inhibits airway hyperresponsiveness induced by ozone exposure
We studied whether ozone-induced hyperresponsiveness could be inhibited by neutrophil depletion in dogs. Responsiveness was assessed with dose-response curves of acetylcholine aerosol versus pulmonary resistance; depletion was assessed by counting neutrophils in venous blood and in biopsies of the airway epithelium. Responsiveness and neutrophil numbers were determined 5 days and 1 day before ozone and 1 h after ozone (3.0 ppm, 2 h) in 6 untreated dogs and in 6 dogs treated with hydroxyurea (200 mg/kg daily for 5 days starting 5 days before ozone). In untreated dogs, responsiveness and neutrophil numbers 5 days and 1 day before ozone did not change, but responsiveness and epithelial neutrophils increased markedly after ozone. In treated dogs, circulating neutrophils decreased from 8.9 +/- 2.2 to 0.6 +/- 0.01 X 10(3) per mm3 (mean +/- SEM), and responsiveness before ozone did not change. Furthermore, increases in responsiveness and epithelial neutrophils did not occur after ozone. Six wk after stopping hydroxyurea, responsiveness and epithelial neutrophils increased markedly after ozone. The results suggest that ozone-induced hyperresponsiveness may depend on the mobilization of neutrophils into the airways.
- Research Organization:
- Department of Medicine, University of California, San Francisco
- OSTI ID:
- 6473930
- Journal Information:
- Am. Rev. Respir. Dis.; (United States), Journal Name: Am. Rev. Respir. Dis.; (United States) Vol. 130:2; ISSN ARRDA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMIDES
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL FUNCTIONS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
DOGS
DOSE-RESPONSE RELATIONSHIPS
FUNCTIONS
HYDROXY COMPOUNDS
HYDROXYUREA
INHIBITION
LEUKOCYTES
MAMMALS
MATERIALS
NEUTROPHILS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OZONE
RESPONSE MODIFYING FACTORS
VERTEBRATES