title: Ozone affects breathing and pulmonary surfactant function in mice.
abstract: The effect on breathing of BALB/c mice immediately following ozone exposure (2 ppm) for 0, 2, 4, 6, and 8 h was studied with a whole body plethysmograph. Whether such exposure affected the normal function of pulmonary surfactant of maintaining airway patency was evaluated with a capillary surfactometer. Respiratory rate in mice that were not exposed was 358+/-16 (mean+/-S.E.) breaths/min and decreased to 202+/-10 after 6 h exposure. The mean pressure change caused by breathing diminished significantly, indicating a reduced tidal volume. BAL fluid from controls maintained patency for 88+/-2% of the study time, 120 s, implying a good surfactant function, but the ozone exposure caused the surfactant to lose its capability of maintaining patency (P < 0.0001). This decaying surfactant function of the BAL fluid coincided with an increasing protein concentration in the fluid of exposed animals (1.46+/-0.14 mg/ml in the 8-h group) as compared to controls (0.44+/-0.04 mg/ml, P < 0.0001). It is concluded that leakage of plasma proteins into the airway lumen was probably the main reason for the surfactant dysfunction, which may have contributed to the altered breathing pattern.
authors.affiliation: The Department of Radiology, Duke University Medical Center, Durham, NC, USA.
authors.forename: W D
authors.initials: WD
authors.lastname: Currie
authors.forename: S M
authors.initials: SM
authors.lastname: van Schaik
authors.forename: I
authors.initials: I
authors.lastname: Vargas
authors.forename: G
authors.initials: G
authors.lastname: Enhorning
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010083:Oxidants, Photochemical / Q000633:toxicity*; D010126:Ozone / Q000633:toxicity*; D011663:Pulmonary Surfactants / Q000032:analysis / Q000502:physiology*; D012119:Respiration / Q000187:drug effects*
chemical_list: D010083:Oxidants, Photochemical; D011663:Pulmonary Surfactants; D010126:Ozone