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Effects of simulated pulmonary surfactant on the cytotoxicity and DNA-damaging activity of respirable quartz and kaolin.
Gao N; Keane MJ; Ong T; Wallace WE
J Toxicol Environ Health, A 2000 Jun; 60(3):153-167
Respirable-sized quartz and kaolin dusts were pretreated with simulated pulmonary surfactant dispersions of dipalmitoyl phosphatidylcholine (DPPC) in saline to model the conditioning of particles depositing in alveolar regions of the lung. DPPC-treated and untreated dusts were used to challenge lavaged rat pulmonary alveolar macrophages in vitro. Cytotoxicity was determined over a 5-d period using both total and viable cell counts from a fluorescence-based viability assay. DNA damage, as an indication of genotoxicity, was determined over a 7-d period by the single-cell gel electrophoresis assay. Untreated quartz and kaolin both expressed a significant and potent cytotoxicity, which increased with concentration and time. DPPC-surfactant pretreatment delayed significant expression of this cytotoxicity until 3 to 5 d after challenge. Untreated quartz also caused DNA damage, which increased with concentration and time. DPPC-surfactant treatment of quartz delayed most DNA damage expression to 5 and 7 d. Untreated kaolin expressed weaker activity for DNA damage, significant at the highest concentration through 5 d, and at the higher concentrations on d 7. Surfactant treatment delayed most kaolin activity for DNA damage to 7 d after challenge.
Simulation methods; Cytotoxicity; Quartz dust; Respirable dust; Models; Laboratory animals; Animals; Animal studies; Lung disorders; Pulmonary system disorders; Respiratory system disorders; In vitro studies
William E. Wallace, NIOSH, 1095 Willowdale Road, Morgantown, WV 26505, USA
Issue of Publication
Journal of Toxicology and Environmental Health, Part A: Current Issues
Page last reviewed: June 15, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division