Documenta Ophthalmologica

, Volume 106, Issue 1, pp 43–50 | Cite as

Retinal pigment epithelial function: a role for CFTR?

  • Sasha Blaug
  • Richard Quinn
  • Judy Quong
  • Stephen Jalickee
  • Sheldon S. Miller
Article

Abstract

In the vertebrate eye, the photoreceptor outer segments and the apical membrane of the retinal pigment epithelium (RPE) are separated by a small extracellular (subretinal) space whose volume and chemical composition varies in the light and dark. Light onset triggers relatively fast (ms) retinal responses and much slower voltage and resistance changes (s to min) at the apical and basolateral membranes of the RPE. Two of these slow RPE responses, the fast oscillation (FO) and the light peak, are measured clinically as part of the electrooculogram (EOG). Both EOG responses are mediated in part by apical and basolateral membranes proteins that form a pathway for the movement of salt and osmotically obliged fluid across the RPE, from retina to choroid. This transport pathway serves to control the volume and chemical composition of the subretinal and choroidal extracellular spaces. In human fetal RPE, we have identified one of these proteins, the cystic fibrosis transmembrane conductance regulator (CFTR) by RT-PCR, immunolocalization, and electrophysiological techniques. Evidence is presented to suggest that the FO component of the EOG is mediated directly or indirectly by CFTR.

retinal pigment epithelium fluid transport EOG cystic fibrosis potassium Cl channels ERG C-wave 

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Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Sasha Blaug
    • 1
  • Richard Quinn
    • 1
  • Judy Quong
    • 2
  • Stephen Jalickee
    • 3
  • Sheldon S. Miller
    • 4
  1. 1.School of Optometry and Department of ZoologyUniversity of TexasAustinUSA
  2. 2.Analytical and Nuclear Chemistry DivisionSchool of Optometry and Lawrence Livermore National LaboratoryLivermoreUSA
  3. 3.School of OptometryUSA
  4. 4.School of Optometry and Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyUSA

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