Antioxidant responsiveness in BALB/c mice exposed to ozone.
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.
Jang
An-Soo
AS
Department of Internal Medicine, Soonchunhyang University Hospital, Bucheon, Korea. jas877@schbc.ac.kr
Choi
Inseon-S
IS
Yang
Sung-Yeul
SY
Kim
Young-Gon
YG
Lee
June-Hyuk
JH
Park
Sung-Woo
SW
Park
Choon-Sik
CS
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
D000975:Antioxidants; D015415:Biomarkers; D010083:Oxidants, Photochemical; D014527:Uric Acid; D008315:Malondialdehyde; D010126:Ozone; D024504:gamma-Tocopherol