The effect of exogenous pulmonary surfactant treatment on acute lung damage associated with the intratracheal instillation of silica.

Details

• Personal Author:
  Antonini JM ; Reasor MJ
• Description:
  Pulmonary exposure of silica results in inflammation, damage to the respiratory epithelium and interstitial matrix, and fibrosis. The surface properties of silica have been shown to play a critical role in its toxicity. The objective of our study was to investigate whether coating the surface of the silica with Survanta, a commercially available, bovine pulmonary surfactant, would reduce the in vitro cytotoxicity to alveolar macrophages, as well as, attenuate the silica-induced lung damage in vivo. In the in vitro studies, alveolar macrophages (AMs) from male Fischer 344 rats were incubated for 1 and 24 hours with native or Survanta-treated silica (0.5 mg/ml). At both time points, the native silica caused a dramatic loss of AM viability. The AMs were protected, however, when the silica was treated with the Survanta. This protective effect was significantly greater after 1 hour when compared after 24 hours. In the in vivo studies, silica ( 10 mg/100 g b wt) was suspended in Survanta (0.5 ml) and intratracheally instilled into the lungs of male Ascher 344 rats. A number of biochemical and cellular parameters were measured within the bronchoalveolar lavage fluid (BALF) 1 and 14 days after the instillation exposures to assess lung damage. One day after the instillations, the Survanta treatment of the silica caused significant reductions in the silica-induced increases in total protein, beta-glucuronidase activity, and the influx of neutrophils (PMNs) into the lungs. Fourteen days after the instillation exposures, this protective effect was lost. When Survanta (0.1 ml in 0.4 ml saline) was instilled into the lungs 15 minutes after the intratracheal instillation of silica ( 10 mg/100 g b wt in 0.5 ml saline), a significant reduction also was demonstrated in the silica-induced elevations in BALF total protein, beta-glucuronidase activity, and the influx of PMNs one day after the instillation exposures. In an attempt to treat silica-exposed lungs, Survanta (0. 1 ml in 0.4 ml of saline) was instilled into the lungs 15 minutes after the silica instillation, and then every other day over a 7- day treatment period. Twenty-four hours after the last Survanta instillation, slight, significant, decreases in the silica-induced elevations in BALF total protein and beta-glucuronidase activity were observed. The Survanta treatment, however, had no effect in preventing the infiltration of PMNs into the lungs. From this investigation using both in vitro and in vivo methodology, a respired silica particle that has adsorbed surfactant may be without an immediate cytotoxic effect, however over time, the surfactant coating of the particle may be removed. and the silica retoxified. [Description provided by NIOSH]
• Subjects:
  Animals Cytotoxins Environmental Exposure Fibrosis Hazardous Substances Laboratories Lung Lung Diseases Occupational Health Respiratory System Respiratory Tract Diseases Risk Assessment Risk Factors Safety Silicon Dioxide Surface-Active Agents

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• Keywords:
  Pulmonary system; Pulmonary system disorders; Exposure levels; Risk factors; Silica; Respiratory system disorders; Fibrosis; Toxins; Surfactants; In vitro study; In vivo study; Cytotoxicity; Animals; Laboratory animals; Cellular function; Lung; Lung function; Proteins
• ISSN:
  1073-449X
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  149
• NIOSHTIC Number:
  nn:20050725
• Citation:
  Am J Respir Crit Care Med 1994 Apr; 149(Abstract Issue):A553
• CAS Registry Number:
  Silica (CAS RN 7631-86-9)
• Federal Fiscal Year:
  1994
• Performing Organization:
  Center to Protect Workers' Rights
• Peer Reviewed:
  False
• Start Date:
  19900928
• Source Full Name:
  American Journal of Respiratory and Critical Care Medicine
• Supplement:
  Abstract Issue
• End Date:
  19970515
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7dc847c09aedf140bc731323e8446b4703641ae07d6ad9e7b7238120dab30b8f7dcaa9b938d34d035f87873a0fe7fec262d5d13dcaf290925445e82b6de3b57d
• Download URL:
  https://stacks.cdc.gov/view/cdc/245953/cdc_245953_DS1.pdf
• File Type:
  [PDF - 168.02 KB ]