Alveolar type II cells: effect of silica.

Details

• Personal Author:
  Ma JY ; Rabovsky J
• Description:
  The role of silica (14808607) in pulmonary disorders at the cellular level was investigated in rat lung. The effect of exposure to silica inhalation on two cytochrome-P450 dependent enzymes (ethoxycoumarin-deethylase and ethoxyphenoxazone-deethylase) in the lung microsomal fraction was studied in male Sprague-Dawley-rats. Exposure to silica had no statistically significant effect on the induction ratio for either activity. Silica exposure may have caused a diminished level of the constitutive enzyme activity in rat lung tissue. Cytochrome-P450 dependent enzymes in the isolated microsomal fraction from whole lung tissue and in isolated rat lung alveolar type-II cells were also studied. Lung microsomal benzyloxyphenoxazone-deethylase was shown to be a nonpolyaromatic hydrocarbon inducible, metyrapone sensitive activity whereas ethoxyphenoxazone-deethylase was a polycyclic aromatic hydrocarbon inducible, alpha-naphthoflavone sensitive form. The alveolar type- II cytochrome-P450 dependent system was tested for its sensitivity to a known purified macrophage secreted compound, platelet activating factor (PAF). PAF exposure enhanced ethoxyphenoxazone- deethylase activity in whole cells but not in microsomal or sonicated whole cell preparations. The effect of PAF may be mediated through a permeability mechanism or through the reversal of an inhibitory process. The authors conclude that a mediator secreted by activated macrophages can affect a critical detoxication mechanism in another cell type of the alveolar region. [Description provided by NIOSH]
• Content Notes:
  in NTRL, no PDF
• Subjects:
  Laboratories Lung Occupational Health Respiratory System Safety Silicon Dioxide
• Keywords:
  NIOSH-Author; Lung-cells; Cell-function; Cell-damage; Silica-dusts; Inhalation-studies; Laboratory-animals; Pulmonary-function
• Document Type:
  Text
• Genre:
  Report
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-40
• NIOSHTIC Number:
  nn:00186101
• NTIS Accession Number:
  PB89188148
• Citation:
  NIOSH 1988 Sep; :1-40
• CAS Registry Number:
  Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  1988
• Peer Reviewed:
  False
• Source Full Name:
  Final Report, Division of Respiratory Disease Studies, NIOSH, 40 pages, 56 references
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7dc847c09aedf140bc731323e8446b4703641ae07d6ad9e7b7238120dab30b8f7dcaa9b938d34d035f87873a0fe7fec262d5d13dcaf290925445e82b6de3b57d
• Download URL:
  https://stacks.cdc.gov/view/cdc/242754/cdc_242754_DS1.pdf
• File Type:
  [PDF - 168.02 KB ]