title: Ozone differentially modulates airway responsiveness in atopic versus nonatopic guinea pigs.
abstract: While acute exposures to ozone (O(3)) can alter airway responsiveness, effects from long-term exposures at low concentrations are less clear. This study assessed whether such exposures could induce nonspecific hyperresponsiveness in nonatopic (nonsensitized) guinea pigs and/or could exacerbate the pre-existing hyperresponsive state in atopic (sensitized) animals, and whether gender was a factor modulating any effect of O(3). Responsiveness was measured during and following exposures to 0.1 and 0.3 ppm O(3) for 4 h/day, 4 days/wk for 24 wk in male and female nonsensitized animals, those sensitized to allergen (ovalbumin) prior to initiation of O(3) exposures, and those sensitized concurrently with exposures. Ozone did not produce hyperresponsiveness in nonsensitized animals, but did exacerbate hyperresponsiveness to both specific and nonspecific bronchoprovocation challenges in sensitized animals, an effect that persisted through at least 4 wk after exposures ended. Gender was not a factor modulating response to O(3). Induced effects on responsiveness were not associated with numbers of eosinophils in the lungs nor with any chronic pulmonary inflammatory response, but were correlated with antigen-specific antibodies in blood. This study supports a role for chronic O(3) exposure in the exacerbation of airways dysfunction in a certain segment of the general population, namely, those demonstrating atopy.
authors.affiliation: Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Schlesinger
authors.forename: Mitchell D
authors.initials: MD
authors.lastname: Cohen
authors.forename: Terry
authors.initials: T
authors.lastname: Gordon
authors.forename: Christine
authors.initials: C
authors.lastname: Nadziejko
authors.forename: Judith T
authors.initials: JT
authors.lastname: Zelikoff
authors.forename: Maureen
authors.initials: M
authors.lastname: Sisco
authors.forename: Jean F
authors.initials: JF
authors.lastname: Regal
authors.forename: Margaret G
authors.initials: MG
authors.lastname: Ménache
mesh_terms: D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D006969:Hypersensitivity, Immediate; D008297:Male; D010083:Oxidants, Photochemical / Q000009:adverse effects*; D010126:Ozone / Q000009:adverse effects*; D012737:Sex Factors
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone