Transmembrane potential of isolated rat alveolar type II cells.

Details

• Personal Author:
  Castranova, Vincent ; Jones GS ; Miles PR
• Description:
  The resting transmembrane potential (Em) of isolated alveolar type- II cells from male Sprague-Dawley-rats was investigated along with the factors which alter this potential. The fluorescent probe, Di-S- C3, was used to determine the Em of the cells. Fluorescence decreased as Em became more negative (hyperpolarization) and increased as Em became more positive (depolarization). At rest the Em was about -27 millivolts (mV) and was dependent on the extracellular potassium concentration, indicating the membrane depolarized as external potassium increased. The cellular preparation in this study contained 85 percent type-II cells with the major contaminating cells being alveolar macrophages and leukocytes, each representing less than 5 percent of the cellular sample. After correcting for this contamination, the estimate of Em was -24mV for type-II cells. The sodium/potassium pump contributed to the electronegativity of the resting Em. Type-II cells were more permeable to potassium than to sodium. A ouabain induced depolarization seemed to result from inhibition of an actual electrogenic sodium/potassium pump. Phorbol-myristate-acetate (PMA) induced sodium dependent membrane depolarization, an increase in the fluorescence of Di-Si-C3. PMA caused a 43 percent increase in oxygen consumption but this was not due to cellular contamination. The authors suggest that it may be possible that sodium dependent depolarization triggers the proliferation of type-II cells occurring after oxidant injury to the lungs. [Description provided by NIOSH]
• Subjects:
  Cells, Cultured Laboratories Lung Occupational Health Respiratory System Safety
• Keywords:
  Alveolar-cells Author Keywords: Membrane Potential Cell-cultures Di-S-C3(5) Electrogenic Pump In-vitro-studies Laboratory-animals Lung-cells Lung-tissue NIOSH-Author Ouabain Oxygen Consumption Phorbol Myristate Acetate

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• ISSN:
  0161-7567
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  ALOSH - Appalachian Laboratory for Occupational Safety and Health
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  54
• Issue:
  6
• NIOSHTIC Number:
  nn:00175516
• Citation:
  J Appl Physiol: Respir Environ Exercise Physiol 1983 Jun; 54(6):1511-1517
• Federal Fiscal Year:
  1983
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1ff02922ebc038fd4fd36c15474e39d7ca63a63dbeebf5f4db674177e62d68d58a299a5be025fd9d4c5a85a346555428541d965529638fac9d10368d2452c361
• Download URL:
  https://stacks.cdc.gov/view/cdc/185377/cdc_185377_DS1.pdf
• File Type:
  [PDF - 1.72 MB ]