Permeability of retinal pigment epithelial cell junctions in the dystrophic rat retina

Ruth B. Caldwell, Barbara J. McLaughlin

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


We have studied permeability of retinal pigment epithelial (RPE) cell junctions in Royal College of Surgeons rats with inherited retinal degeneration, and their genetic controls, using the horseradish peroxidase and lanthanum nitrate electron microscope tracer techniques. We find that early in the dystrophic process, at two postnatal weeks in the pink-eyed retina and three postanatal weeks in the black-eyed retina, RPE cell tight junctions form a barrier to extracellular tracer. However, at three postnatal weeks in the pink-eyed retina, at about the same time that degenerating photoreceptor nuclei begin to appear, RPE cell tight junctions become permeable. The permeability increase occurs later in the black-eyed strain, but by six postnatal weeks junctions are permeable in both strains. By 72 postnatal days, when most photoreceptor nuclei have disappeared, many RPE cells are abnormal in shape, with an elongated and flattened appearance, and some appear to have lost their junctions entirely. In the horseradish peroxidase experiments, many pinocytotic vesicles filled with reaction product were observed in the dystrophic RPE after the junctional breakdown. This suggests that an increase in transcellular transport may also occur in the dystrophic RPE.

Original languageEnglish (US)
Pages (from-to)415-427
Number of pages13
JournalExperimental eye research
Issue number3
StatePublished - Mar 1983
Externally publishedYes


  • blood-retinal barrier
  • dystrophic rat
  • electron microscope tracers
  • horseradish peroxidase
  • lanthanum nitrate
  • permeability
  • retinal pigment epithelium
  • tight junctions

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience


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