Differential expression of sodium pump catalytic subunits in the lens epithelium and fibers

Nicholas A Delamere, W. L. Dean, J. M. Stidam, A. E. Moseley

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Na,K-ATPase in lens epithelium plays a key role in conducting sodium-potassium transport. The purpose of this study was to test whether epithelium or fiber cells can synthesize new Na,K-ATPase protein in response to an increase of membrane permeability. Western blot methodology was used to identify Na,K-ATPase α subunit polypeptides in membrane material isolated from lens cells. As judged by immunoblot density, epithelial cell membrane material isolated from porcine lenses cultured 24 h with 1 μM amphotericin B contained more Na,K-ATPase a subunit polypeptide than epithelial material isolated from control lenses. This increase stemmed from the apparent synthesis of Na,K-ATPase α2 isoform polypeptide by the epithelium; Na,K-ATPase α1 isoform polypeptide abundance was not detectably altered. The apparent amphotericin B-induced expression of Na,K-ATPase α2 was seen in lens epithelial cells but not fiber cells. This study suggests that the epithelium of the adult porcine lens may be capable of expressing additional sodium pump molecules of the α2-subtype when membrane permeability is increased.

Original languageEnglish (US)
Pages (from-to)73-76
Number of pages4
JournalOphthalmic Research
Volume28
Issue numberSUPPL. 1
Publication statusPublished - Mar 1996
Externally publishedYes

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Keywords

  • Amphotericin B
  • Lens
  • Membrane permeability
  • Na,K-ATPase

ASJC Scopus subject areas

  • Ophthalmology

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