Contrasting respirable quartz and kaolin retention of lecithin surfactant and expression of membranolytic activity following phospholipase A2 digestion

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• Personal Author:
  Hill CA ; Keane MJ ; Mike PS ; Regad ED ; Vallyathan V ; Wallace WE
• Description:
  The rates of digestive removal of dipalmitoyl-lecithin (DPL), a component of pulmonary surfactant, by phospholipase-A2 (PLA2) and recovery of membranolytic activity for a quartz (14808607) and a kaolin (1332587) dust were compared. Stock dispersion of DPL in physiologic saline was generated by sonication. Dry silica or kaolin mineral dusts were vortexed into emulsions of DPL/saline. DPL treated kaolin and quartz were incubated with PLA2 for periods of 2 to 72 hours at different applied enzyme concentrations. The hemolytic potentials of the mineral dusts were determined by an erythrocyte hemolytic assay. A rapid loss of adsorbed DPL in the first 2 hours of incubation with PLA2 was observed for both quartz and kaolin dusts. This was followed by a slower loss of the remaining DPL. The rate of DPL removal increased with increasing applied concentrations of enzyme for incubation times greater than 2 hours. DPL removal rates were greater for quartz bound than for kaolin bound DPL. The hemolytic activity of treated quartz was greater than the native quartz activity for all three enzyme levels at 2 and 22 hours, and treated quartz activity roughly equaled that of native quartz at 44 and 72 hours. The hemolytic activity of treated kaolin was greater than the native kaolin activity at 2 hours. Significantly decreased hemolytic activities for digestion times greater than 2 hours for the two lower enzyme levels were observed in DPL coated kaolin. [Description provided by NIOSH]
• Subjects:
  Blood Dust Hazardous Substances Lipids Lung Occupational Health Respiratory System Safety Silicon Dioxide Surface-Active Agents Toxicology

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• Keywords:
  Comparative-toxicology Hemolysis Mineral-dusts NIOSH-Author Phospholipids Plasma-membrane Pulmonary-system Respirable-dust Silica-dusts Surfactants Toxic-effects

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• ISSN:
  0098-4108
• Document Type:
  Text
• Genre:
  Journal Article
• 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:
  391-409
• Volume:
  37
• Issue:
  3
• NIOSHTIC Number:
  nn:00211278
• Citation:
  J Toxicol Environ Health 1992 Nov; 37(3):391-409
• CAS Registry Number:
  Kaolin (CAS RN 1332-58-7) ; Quartz (SiO2) (CAS RN 14808-60-7)
• Federal Fiscal Year:
  1993
• NORA Priority Area:
  Pulmonary System Disorders
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Toxicology and Environmental Health
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a47e422f5cc4ad5af062ef09ed0fecba4c8926db9b426ceff59443ea8588dcb0302aeab8cd9f0681a45978ae60221e65d6125562bfd9f91622bb86bd7f685741
• Download URL:
  https://stacks.cdc.gov/view/cdc/204397/cdc_204397_DS1.pdf
• File Type:
  [PDF - 1.11 MB ]