Single potassium channels blocked by lidocaine and quinidine in isolated turtle colon epithelial cells

N. W. Richards, D. C. Dawson

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The patch-clamp technique for recording single-channel currents across cell membranes was applied to single turtle colon epithelial cells isolated with hyaluronidase. With electrodes fabricated from Corning #7052 glass, high-resistance seals were consistently formed to these cells. In on-cell patches with low K (2.5 mM) in the pipette and high K (114.5 mM) in the bath, outward K currents were recorded that had a slope conductance of 17 pS and a reversal potential greater than -70 mV. Currents through this K channel were blocked by lidocaine, quinidine, and barium. These agents also block a cell swelling-induced K conductance identified by macroscopic current measurements in the basolateral membranes of the intact colonic epithelium, suggesting that the 17 pS K channel identified by single-channel recording in isolated turtle colon cells may be responsible for this macroscopically defined K conductance.

Original languageEnglish (US)
Pages (from-to)20/1
JournalAmerican Journal of Physiology - Cell Physiology
Issue number1
StatePublished - Jan 1 1986


ASJC Scopus subject areas

  • Physiology
  • Cell Biology

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