An outwardly rectifying and deactivating chloride channel expressed by interstitial cells of cajal from the murine small intestine

J Membr Biol. 2008 Feb;221(3):123-32. doi: 10.1007/s00232-007-9084-2. Epub 2008 Feb 14.


Recent studies have suggested a role for a chloride current in the modulation of pacemaker potentials generated by interstitial cells of Cajal. Patch-clamp recordings were made from inside-out patches of cultured interstitial cells of Cajal from the murine small intestine. The majority of patches were quiescent immediately after excision, but in some patches currents activated spontaneously after a period of 10 min to 1 h. Currents could also be activated by strongly polarizing the patch. It was found that the currents activated in both cases included a chloride channel. This channel could also be activated by ATP and the catalytic subunit of protein kinase A. The channel had conductance states (+/-SD) of 53 +/- 25.35, 126 +/- 21.44, 180 +/- 12.57 and 211 +/- 8.86 pS. It was outwardly rectifying (as a function of open probability) and deactivated (i.e., gave a tail current) but showed no inactivation. The permeability sequence of the channel was I(-)>>Br(-)>or=Cl(-)>Asp(-). It was unaffected in magnitude or rectification by changing the free Ca2+ concentration of the bath between <10 nM, 100 nM (control) and 2 mM .

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Anions / metabolism
  • Calcium / metabolism
  • Cell Membrane Permeability / drug effects
  • Cell Membrane Permeability / physiology*
  • Cells, Cultured
  • Chloride Channels / metabolism*
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / metabolism
  • Jejunum / cytology
  • Jejunum / metabolism*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology*
  • Mice
  • Mice, Inbred BALB C
  • Patch-Clamp Techniques
  • Time Factors


  • Anions
  • Chloride Channels
  • Adenosine Triphosphate
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits
  • Calcium