Circulating factors that modify lung cell DNA synthesis following exposure to inhaled oxidants. II. Effect of serum and lavage on lung pneumocytes following exposure of adult rats to 1 ppm ozone

• Published in: Journal of toxicology and environmental health Vol. 29; no. 1; p. 131
• Main Authors: Tanswell, A K, Fraher, L J, Grose, E C
• Format: Journal Article
• Language: English
• Published: United States 1990
• Subjects: Administration, Inhalation; Animals; Bronchoalveolar Lavage Fluid; Chromatography, High Pressure Liquid; DNA - biosynthesis; DNA - metabolism; Isoelectric Focusing; Lung - drug effects; Lung - metabolism; Male; Ozone - administration & dosage; Ozone - toxicity; Rats; Time Factors
• ISSN: 0098-4108
• DOI: 10.1080/15287399009531377

Adult rats were exposed to 1 ppm (1.96 mg/m3) ozone or air for 2 wk. Animals were sacrificed at 3, 5, 7, or 14 d after the onset of exposure, and samples of plasma and lung lavage were obtained. Heat-inactivated plasma and lavage from animals exposed to ozone for 5 or 7 d significantly increased DNA synthesis by lung pneumocytes compared with plasma or lavage from air-exposed animals. Fractionation of plasma and lavage samples indicated that the factor responsible had an isoelectric point of 6.45-6.75, and a molecular weight of 38 +/- 3 kDa. This factor has a dose-dependent effect on lung pneumocyte DNA synthesis in culture. It has no effect on cultured fibroblast DNA synthesis, and is distinct from a previously described factor in the plasma of these ozone-exposed animals that enhances fibroblast DNA synthesis. The factor is detectable within 5 d of exposure, and may hold some promise as a marker of early oxidant lung injury.