title: Low-level subchronic exposure to wood smoke exacerbates inflammatory responses in allergic rats.
abstract: Epidemiological studies have implicated wood smoke as a risk factor for exacerbating asthma. However, comparisons of findings in animal models with those in humans are currently not possible, because detailed clinically relevant measurements of pulmonary function are not available in animal studies. Brown Norway rats were immunized with ovalbumin and exposed to either filtered air or wood smoke at 1 mg particulate matter/m(3) for 70 days and challenged with allergen during the last 4 days of exposure. Baseline values for dynamic lung compliance were lower while functional residual capacity was increased in rats exposed to wood smoke compared to rats exposed to filtered air. IFN-gamma levels were reduced and IL-4 levels increased in the bronchoalveolar lavage fluid and blood plasma, inflammatory lesions in the lungs were 21% greater, and airway mucous cells/mm basal lamina were non-significantly increased in rats exposed to wood smoke compared to controls. Collectively, these studies suggest that the pulmonary function was affected in rats by exposure to wood smoke and this decline was associated with only minor increases in inflammation of the lung. Therefore, this animal model may be useful to elucidate the mechanisms of the decline in pulmonary function caused by environmental pollutants when asthmatics are exposed to allergen.
authors.affiliation: Lovelace Respiratory Research Institute, Albuquerque, NM 87108, USA. ytesfaig@lrri.org
authors.forename: Yohannes
authors.initials: Y
authors.lastname: Tesfaigzi
authors.forename: Jacob D
authors.initials: JD
authors.lastname: McDonald
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Reed
authors.forename: Shashibhushan P
authors.initials: SP
authors.lastname: Singh
authors.forename: George T
authors.initials: GT
authors.lastname: De Sanctis
authors.forename: Paul R
authors.initials: PR
authors.lastname: Eynott
authors.forename: Fletcher F
authors.initials: FF
authors.lastname: Hahn
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Campen
authors.forename: Joe L
authors.initials: JL
authors.lastname: Mauderly
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D000485:Allergens / Q000494:pharmacology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D019570:Inhalation Exposure; D007371:Interferon-gamma / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D008297:Male; D010047:Ovalbumin / Q000494:pharmacology; D051381:Rats; D011914:Rats, Inbred BN; D012129:Respiratory Function Tests; D012130:Respiratory Hypersensitivity / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000473:pathology; D012906:Smoke / Q000009:adverse effects* / Q000032:analysis; D014934:Wood
chemical_list: D000393:Air Pollutants; D000485:Allergens; D012906:Smoke; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin