title: Interaction of ozone exposure with airway hyperresponsiveness and inflammation induced by trimellitic anhydride in sensitized guinea pigs.
abstract: The effect of prior ozone (O3) exposure on airway hyperresponsiveness and inflammation induced by trimellitic anhydride (TMA) has been investigated in TMA-sensitized guinea pigs. Airway responsiveness was measured as the concentration of acetylcholine needed to increase baseline lung resistance (RL) by 300% (PC300). Ozone (3 ppm for 3 h) caused an increase in -log PC300 at 1 h after exposure, with return of -log PC300 to control levels at 8 h. Ozone also increased baseline RL at 8 h. TMA challenge increase -log PC300 in TMA-sensitized guinea pigs at 8 h after challenge from 3.85 +/- 0.09 to 4.11 +/- 0.09. Ozone exposure prior to TMA challenge prevented the induction of airway hyperresponsiveness with a mean -log PC300 of 3.51 +/- 0.20, which was not different from that of control TMA-sensitized group. Baseline RL was significantly higher in ozone-pretreated animals after TMA challenge when compared to those of either control or challenged with TMA alone. Ozone had no effect on TMA challenge-induced BAL eosinophilia and neutrophilia. We conclude that a single exposure to ozone inhibits the increase in airway responsiveness but increases the bronchoconstrictor response induced by TMA in TMA-sensitized guinea pigs; however, the inflammatory airway response to TMA is unchanged by preexposure to ozone.
authors.affiliation: Department of Thoracic Medicine, National Heart & Lung Institute, London, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: K F
authors.initials: KF
authors.lastname: Chung
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000403:Airway Resistance / Q000187:drug effects; D000485:Allergens / Q000008:administration & dosage*; D000818:Animals; D001249:Asthma / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D001991:Bronchitis / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004195:Disease Models, Animal; D004347:Drug Interactions; D004802:Eosinophilia / Q000139:chemically induced; D006168:Guinea Pigs; D007958:Leukocyte Count; D008168:Lung / Q000187:drug effects*; D008297:Male; D009504:Neutrophils / Q000187:drug effects; D010083:Oxidants, Photochemical / Q000494:pharmacology*; D010126:Ozone / Q000494:pharmacology*; D010796:Phthalic Anhydrides / Q000008:administration & dosage*
chemical_list: D000485:Allergens; D010083:Oxidants, Photochemical; D010796:Phthalic Anhydrides; D010126:Ozone; C015559:trimellitic anhydride; D000109:Acetylcholine