Sodium permeability of dog red blood cell membranes. I. Identification of regulatory sites

Details

• Personal Author:
  Castranova, Vincent ; Miles PR
• Description:
  Divalent cations and group-specific chemical modifiers were used to modify sodium efflux in order to probe the molecular structure of sodium channels in dog red blood cells. Hg++, Ni++, Co++, and PCMBS (parachloromercuribenzene sulfonic acid), a sulfhydryl reactive reagent, induce large increases in Na+ permeability and their effects can be described by a curve which assumes 2:1 binding with the sodium channel. The sequence of affinities, as measured by the dissociation constants, reflects the reactivity of these divalent cations with sulfhydryl groups. In addition, the effects of Hg++ and PCMBS can be reversed by the addition of dithiothreitol, an SH-containing compound, to the medium. Much smaller increases in Na+ permeability are produced by Zn++ and the amino-specific reagents, TNBS (2,4,6-trinitrobenzene sulfonic acid) and SITS (4-acetamido-4'-isothiocyano-stilbene-2-2'-disulfonic acid). The Zn++ effect can be described by a curve which assumes bimolecular binding with the channel, and its effect on Na+ permeability can be reversed by the addition of glycine to the medium. The effects of Ni++ and SITS can be completely reversed by washing the cells in 0.16 M NaCl while TNBS binding is partially irreversible. Measurements of mean cell volumes (MCV) indicate that the modifier-induced increases in Na+ permeability are not caused by shrinkage of the cells. It is concluded that the movement of sodium ions through ionic channels in dog red blood cells can be enhanced by modification of amino and sulfhydryl groups. Zn++, TNBS, and SITS increase Na+ permeability by modifying amino groups in the channel while Hg++, Ni++, Co++, and PCMBS act on sulfhydryl groups. [Description provided by NIOSH]
• Subjects:
  Animals Energy Metabolism Laboratories Mercury Metals Nitrogen Compounds Occupational Health Safety Zinc Compounds
• Keywords:
  Animal-studies Cobalt-compounds Copper-compounds Laboratory-animals Mercury-compounds Metabolic-study Metabolism Nitrogen-compounds Sodium-compounds Zinc-compounds
• ISSN:
  0022-1295
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  ALFORD - Appalachian Laboratory for Occupational Respiratory Disease
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  67
• Issue:
  5
• NIOSHTIC Number:
  nn:20047419
• Citation:
  J Gen Physiol 1976 May; 67(5):563-578
• Federal Fiscal Year:
  1976
• Peer Reviewed:
  True
• Source Full Name:
  Journal of General Physiology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:311e98d52e4c6b439ad3ed3b0ee064115cba2520e9eac2d59e385baaa83e252ef1ce43b1ea10cc9f8b74aeacc7ce2569886bf2c5a8fd25f7fcd47b0d80396700
• Download URL:
  https://stacks.cdc.gov/view/cdc/202486/cdc_202486_DS1.pdf
• File Type:
  [PDF - 905.19 KB ]