title: Antioxidant responsiveness in BALB/c mice exposed to ozone.
abstract: BACKGROUND
  A single, acute exposure to ozone has been shown to modify the antioxidant defense mechanism in the respiratory tract.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the effects of ozone exposure on antioxidant response in BALB/c mice.
  
  
  METHODS
  We measured enhanced pause of breathing (Penh) as a marker of airway obstruction using barometric whole-body plethysmography before and after ozone exposure [groups (n = 6): filtered air, 0.12 ppm, 0.5 ppm, 1 ppm, 2 ppm] for 3 h. Antioxidant levels were measured using high-performance liquid chromatography with electrochemical detection in bronchoalveolar lavage (BAL) fluid and lung tissue homogenates.
  
  
  RESULTS
  Malondialdehyde concentrations in lung tissue homogenates were significantly increased in the group exposed to 2-ppm ozone compared to the filtered air group. Uric acid and gamma-tocopherol concentrations in BAL fluid were significantly increased in the ozone exposure group compared to the filtered air group (p < 0.01). Uric acid concentrations were increased in a concentration-dependent manner according to ozone concentration to which the animals were exposed. Increases in Penh after ozone exposure were significantly higher in an ozone concentration-dependent manner. The proportion of neutrophils in BAL fluid was significantly higher in the group exposed to 2 ppm than in the filtered air and the group exposed to 0.12 ppm (p < 0.01, respectively). The level of ascorbate correlated with the level of gamma-tocopherol.
  
  
  CONCLUSIONS
  These findings suggest that antioxidant responses may serve as a protective mechanism against a range of oxidants in BALB/c mice exposed to ozone.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Hospital, Bucheon, Korea. jas877@schbc.ac.kr
authors.forename: An-Soo
authors.initials: AS
authors.lastname: Jang
authors.forename: Inseon-S
authors.initials: IS
authors.lastname: Choi
authors.forename: Sung-Yeul
authors.initials: SY
authors.lastname: Yang
authors.forename: Young-Gon
authors.initials: YG
authors.lastname: Kim
authors.forename: June-Hyuk
authors.initials: JH
authors.lastname: Lee
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Choon-Sik
authors.initials: CS
authors.lastname: Park
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000166:cytology; D010083:Oxidants, Photochemical / Q000008:administration & dosage / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010126:Ozone / Q000008:administration & dosage / Q000633:toxicity*; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D014527:Uric Acid / Q000378:metabolism; D024504:gamma-Tocopherol / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D010083:Oxidants, Photochemical; D014527:Uric Acid; D008315:Malondialdehyde; D010126:Ozone; D024504:gamma-Tocopherol