Transient outwardly rectifying potassium channel in the rabbit corneal endothelium

Mitchell Aaron Watsky, Kim Cooper, James L. Rae

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Ionic currents from freshly dissociated rabbit corneal endothelial cells were examined using patch-clamp technology and a perforated patch technique. Whole-cell current recordings revealed a transient outward K+-selective current that was blockable in a dose-dependent manner by 4-aminopyridine (4-AP) and quinidine. This current is similar to the 'A'-type current present in many excitable cells and is the first reported instance of such a current in any epithelial cell type. In addition to the transient current, an outwardly rectifying nonselective cation current was also observed. This current is also blocked by quinidine. To examine the possible role of these currents in the stromal volume regulatory function of the endothelium, corneas were perfused under a specular microscope with a glutathionebicarbonate Ringer's solution (GBR) or GBR plus either 1 mM quinidine or 10 mM 4-AP. For quinidine perfusions, control corneas swelled at a rate of 6 μm/hr, while quinidine-perfused corneas swelled at a rate of 48 μm/hr. For 4-AP perfusions, control corneas deswelled at a rate of -2 μm/hr, while 4-AP perfused corneas swelled at a rate of 24 μm/hr. One possible mechanism of the stromal swelling induced by these K+ channel blockers may be the result of loss of the K+ recycling pathway necessary for proper Na+/K+ ATPase function.

Original languageEnglish (US)
Pages (from-to)123-132
Number of pages10
JournalThe Journal of Membrane Biology
Volume128
Issue number2
DOIs
StatePublished - Jun 1 1992
Externally publishedYes

Fingerprint

Corneal Endothelium
Quinidine
Potassium Channels
4-Aminopyridine
Cornea
Rabbits
Perfusion
Patch-Clamp Techniques
Endothelium
Cations
Endothelial Cells
Epithelial Cells
Technology

Keywords

  • A-type potassium channel
  • cornea
  • epithelium
  • patch clamp
  • perforated patch

ASJC Scopus subject areas

  • Physiology
  • Cell Biology
  • Biophysics

Cite this

Transient outwardly rectifying potassium channel in the rabbit corneal endothelium. / Watsky, Mitchell Aaron; Cooper, Kim; Rae, James L.

In: The Journal of Membrane Biology, Vol. 128, No. 2, 01.06.1992, p. 123-132.

Research output: Contribution to journalArticle

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