Calcium-dependent regulation of membrane ion permeability in a cell line derived from the equine sweat gland epithelium

Stuart M. Wilson, Wing Hung Ko, John D. Pediani, Soma Rakhit, James A. Nichol, Douglas Bovell

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16 Citations (Scopus)


We measured the rates of 125I- and 86Rb+ efflux from preloaded, cultured equine sweat gland cells. The calcium ionophore ionomycin increased the efflux of both isotopes. Anion efflux was unaffected by Ba2+, but this cation inhibited 86Rb+-efflux, suggesting that [Ca2+]i-activated potassium channels were present. Activation of these channels was not, however, important for the efflux of anions. We measured 125I- efflux from valinomycin-depolarised cells in which anion cotransport was inhibited. Changes in 125I- efflux reflect changes in anion permeability under these conditions, and ionomycin caused a clear permeability increase that was abolished by the anion channel blocker diphenylamine-2-carboxylate. ATP and UTP increased the efflux of both isotopes, suggesting that type P2U purine receptors allow these nucleotides to regulate membrane permeability.

Original languageEnglish
Pages (from-to)215-221
Number of pages7
JournalComparative Biochemistry and Physiology -- Part A: Physiology
Issue number2
Publication statusPublished - 1995
Externally publishedYes



  • I-efflux
  • Rb-efflux
  • Cell culture
  • Intracellular Ca
  • Membrane permeability
  • Purinergic receptors
  • Stimulus-secretion coupling
  • Sweat gland

ASJC Scopus subject areas

  • Physiology

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