Basolateral Na-H antiporter: Uncoupled Na transport produces an amiloride- sensitive conductance

M. A. Post, D. C. Dawson

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

An amiloride-inhibitable, Na+-H+ antiporter was identified in the basolateral membrane of turtle colon by measuring 22Na+ fluxes across isolated tissues apically permeabilized with the pore-forming antibiotic amphotericin B. In cells shrunken by exposure to Cl--free (gluconate) solutions and treated with ouabain to block the Na-K-ATPase, Na+ movement across the basolateral membrane was due entirely to the antiporter. Elevation of cytosolic Na+ was associated with an amiloride-inhibitable outward current across the basolateral membrane. The sensitivity of the current to various amiloride analogues paralleled that of Na+ exchange rather than that of the apical Na+ channel. Furthermore, cell volume changes altered basolateral Na+ exchange and basolateral Na+ conductance in a parallel fashion. We propose that this amiloride-sensitive basolateral Na+ conductance represents an altered operating mode of a basolateral Na+-H+ exchanger.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume262
Issue number4 31-4
StatePublished - 1992
Externally publishedYes

Fingerprint

Sodium-Hydrogen Antiporter
Amiloride
Membranes
Antiporters
Turtles
Amphotericin B
Ouabain
Cell Size
Colon
Tissue
Fluxes
Anti-Bacterial Agents

Keywords

  • antiport
  • carrier
  • cell volume
  • channel
  • electrodiffusion
  • exchange
  • pH
  • pore
  • slip
  • sodium-sodium exchange

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry
  • Physiology

Cite this

Basolateral Na-H antiporter : Uncoupled Na transport produces an amiloride- sensitive conductance. / Post, M. A.; Dawson, D. C.

In: American Journal of Physiology - Cell Physiology, Vol. 262, No. 4 31-4, 1992.

Research output: Contribution to journalArticle

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