Effect of volume changes on a potassium current in rabbit corneal epithelial cells

G. Farrugia, J. Rae

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22 Scopus citations


Patch-clamp recordings from rabbit corneal epithelial cells have identified a large-conductance (167 pS in symmetrical 150 mM KCl) K channel that is the major contributor to the whole cell current (J. L. Rae and G. Farrugia. J. Membr. Biol. 129: 81-87, 1992). We report here on the regulation of this channel by changes in cellular osmolality and/or volume. Exchanging the bath solution with a hyposmotic (225 or 150 mosM) solution resulted in cellular swelling and selective activation of the K current (126 ± 86 and 273 ± 184% increase, respectively). Hyperosmotic solution changes (380 mosM) resulted in cell shrinkage and deactivation of the K current (44.2 ± 21% decrease). Similar increases in the cell volume and whole cell current were observed on increasing (in perforated patch experiments) the chloride ion concentration (50 mM) in the pipette intracellular solution (127 ± 63% increase). These changes were accompanied by marked shifts in the resting membrane voltage. We conclude that the K channels in these cells can respond to alteration in cellular osmolality or volume, resulting in changes in the whole cell current and resting voltage.

Original languageEnglish (US)
Pages (from-to)C1238-C1245
JournalAmerican Journal of Physiology - Cell Physiology
Issue number5 33-5
StatePublished - 1993


  • channels
  • corneal epithelium
  • osmolar changes
  • patch clamp
  • volume regulation

ASJC Scopus subject areas

  • Physiology
  • Cell Biology


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