Sodium channels in ocular epithelia

Mitchell A. Watsky, Kim Cooper, James L. Rae

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

Voltage-gated, tetrodotoxin(TTX)-blockable sodium channels are found in most excitable cells and are the primary contributors to action potentials generated by many of these cells. To date, there has only been one report of a non-cultured vertebrate epithelial cell type containing TTX-blockable Na+ channels: rabbit non-pigmented ciliary body epithelial cells [Cilluffo MC et al. (1991) Invest Opthalmol Vis Sci 32:1619-1629], and three reports of cultured epithelial cells containing TTX-blockable Na+ channels: rabbit non-pigmented and pigmented ciliary body epithelium [Ciluffo MC et al. (1991) Invest Opthalmol Vis Sci 32:1619-1629; Fain GL, Farahbakhsh (1989) J Physiol (Lond) 417:83-103] and human lens epithelium [Cooper K et al. (1990) J Membr Biol 117:285-298]. We report here the presence of sodium currents in two different non-cultured, freshly dissociated transporting epithelial cell types: the rabbit corneal endothelium and the frog lens epithelium. We also report the occurrence of sodium currents in six additional cultured ocular epithelial cell types from three different species. These currents have a current/voltage (I/V) relationship consistent with traditional voltage-gated Na+ currents, are quinidine- and TTX-blockable (of the low-affinity TTX-sensitive type), and disappear following bath substitution of Na+ with Cs+ or K+.

Original languageEnglish (US)
Pages (from-to)454-459
Number of pages6
JournalPflügers Archiv European Journal of Physiology
Volume419
Issue number5
DOIs
StatePublished - Nov 1 1991
Externally publishedYes

Keywords

  • Ciliary body epithelium
  • Corneal endothelium
  • Lens epithelium
  • Na channel
  • Tetrodotoxin

ASJC Scopus subject areas

  • Physiology
  • Clinical Biochemistry
  • Physiology (medical)

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