title: Time course of pulmonary response of rats to inhalation of crystalline silica: histological results and biochemical indices of damage, lipidosis, and fibrosis.
abstract: Previous studies have determined that alpha-quartz (crystalline silica) can cause pulmonary inflammation, damage, and fibrosis. However, the temporal relationship between silica inhalation and pulmonary inflammation, damage, and fibrosis has not been fully examined. To address this gap in our knowledge of silica-induced pulmonary fibrosis, a chronic inhalation study using rats was designed. Specifically, rats were exposed to a silica aerosol (15 mg/m3 silica, 6 h/d, 5 d/wk, 116 d), and measurements of pulmonary inflammation, damage, and fibrosis were monitored throughout the study. We report (1) data demonstrating that the silica aerosol generation and exposure system produced a consistent silica aerosol of respirable size particles; (2) the time course of silica deposition in the lung; (3) calculations that demonstrate that the rats were not in pulmonary overload; (4) histopathological data demonstrating time-dependent enhancement of silica-induced alveolitis, epithelial hypertrophy and hyperplasia, alveolar lipoproteinosis, and pulmonary fibrosis in the absence of overload; and (5) biochemical data documenting the development of lipidosis, lung damage, and fibrosis.
authors.affiliation: National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Morgantown, WV 26505, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Porter
authors.forename: D
authors.initials: D
authors.lastname: Ramsey
authors.forename: A F
authors.initials: AF
authors.lastname: Hubbs
authors.forename: L
authors.initials: L
authors.lastname: Battelli
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: M
authors.initials: M
authors.lastname: Barger
authors.forename: D
authors.initials: D
authors.lastname: Landsittel
authors.forename: V A
authors.initials: VA
authors.lastname: Robinson
authors.forename: J
authors.initials: J
authors.lastname: McLaurin
authors.forename: A
authors.initials: A
authors.lastname: Khan
authors.forename: W
authors.initials: W
authors.lastname: Jones
authors.forename: A
authors.initials: A
authors.lastname: Teass
authors.forename: V
authors.initials: V
authors.lastname: Castranova
mesh_terms: D000280:Administration, Inhalation; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000818:Animals; D001822:Body Burden; D018893:Bronchoalveolar Lavage; D008064:Lipidoses / Q000139:chemically induced; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D010316:Particle Size; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D012822:Silicon Dioxide / Q000008:administration & dosage / Q000633:toxicity*; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors
chemical_list: D000395:Air Pollutants, Occupational; D012822:Silicon Dioxide