Remodelling of the retinal pigment epithelium in response to intraepithelial capillaries: evidence that capillaries influence the polarity of epithelium

• Published in: Cell and tissue research Vol. 245; no. 1; p. 135
• Main Authors: Korte, G E, Bellhorn, R W, Burns, M S
• Format: Journal Article
• Language: English
• Published: Germany 01.01.1986
• Subjects: Animals; Capillaries - physiology; Capillaries - ultrastructure; Cell Membrane - ultrastructure; Microscopy, Electron; Pigment Epithelium of Eye - blood supply; Pigment Epithelium of Eye - cytology; Pigment Epithelium of Eye - ultrastructure; Rats; Rats, Inbred Strains
• ISSN: 0302-766X
• DOI: 10.1007/BF00218094

Light- and urethane-induced retinopathies in rats are characterized by loss of photoreceptors. Retinal capillaries subsequently become incorporated into the normally avascular retinal pigment epithelium. These models provided an opportunity to study the response of epithelial cells to closely apposed capillaries, in order to determine if capillaries contribute to the polar organization of epithelial cells. Pigment epithelial cells reorganized their lateral plasma membrane where the latter faced intraepithelial capillaries. This normally flat, undifferentiated membrane developed attachment sites, folds and intracytoplasmic tubules, and exhibited endocytosis and putative basal lamina secretion. These structural and functional specializations are normally restricted to the basal plasma membrane - the normal vascular front of the cell facing the dense meshwork of capillaries constituting the choriocapillaris. We conclude that RPE cells, and perhaps epithelia in general, polarize in response to an adjacent capillary bed.