Control of potassium transport by turtle colon: Role of membrane potential

D. R. Halm, D. C. Dawson

Research output: Contribution to journalArticlepeer-review

Abstract

To more clearly define the role of the transepithelial electrical potential difference (V(m→s)), potassium permeability, and sodium potassium pump rate in transcellular potassium transport by isolated turtle colon, we measured transmural potassium fluxes under open-circuit conditions in the presence and absence of putative blockers of potassium transport: amiloride and barium. The results were consistent with the notion that V(m→s) is a major determinant of cellular potassium secretion, whereas active potassium absorption is insensitive to changes in V(m→s). These observations suggest that 'coupling' between colonic sodium absorption and potassium secretion in vivo could be due primarily to the effect of the lumen negative V(m→s) on transcellular secretory potassium flow. Amiloride-induced inhibition of potassium secretion appeared to be due to the reductions in V(m→s) and sodium-potassium pump rate that accompanied the inhibition of active sodium absorption.
Original languageEnglish
Pages (from-to)C26-C32
JournalAmerican Journal of Physiology - Cell Physiology
Volume247
Issue number1
DOIs
StatePublished - 1984
Externally publishedYes

ASJC Scopus Subject Areas

  • Physiology (medical)

Keywords

  • Active Transport
  • Amiloride
  • Potassium Secretion
  • Pseudemys scripta
  • Amiloride / pharmacology
  • Anmals
  • Barium / pharmacology
  • Biological Transport, Active
  • Cell Membrane Pereability
  • Colon / drug effects
  • Colon / metabolism*
  • Ion Channels / drug effects
  • Ion Channels / physiology
  • Membrane Potentials
  • Potassium / antagonists & inhibitors
  • Potassium / metabolism*
  • Sodium / metabolism
  • Trutles / metabolism*
  • Ion Channels
  • Barium
  • Sodium
  • Potassium

Disciplines

  • Medical Cell Biology
  • Medical Neurobiology
  • Medical Physiology
  • Neurosciences
  • Physiological Processes

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