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

M. A. Post, D. C. Dawson

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


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)
Pages (from-to)C1089-C1094
JournalAmerican Journal of Physiology - Cell Physiology
Issue number4 31-4
StatePublished - 1992


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

ASJC Scopus subject areas

  • Physiology
  • Cell Biology


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