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Updated: Aug 24, 2026

Endothelial Cell Transcytosis Assay as an In Vitro Model to Evaluate Inner Blood-Retinal Barrier Permeability
Published on: June 7, 2022
Endothelin-1 distribution and basolateral secretion in the retinal pigment epithelium
Santosh Narayan1, Anne Marie Brun, Thomas Yorio
1Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
Abstract:
Endothelins are a family of conserved vasoactive peptides that are widely expressed in different biological systems including the eye. In the cell culture model of retinal pigment epithelium, ARPE-19, the synthesis and secretion of endothelin-1 (ET-1) is regulated by cholinergics and TNF-alpha. In the present study we investigated the expression of ET-1 in RPE in situ, in rat and human eyes. Additionally, we have employed the human retinal pigment epithelial (ARPE-19) cells to delineate the apical and basolateral ET-1 expression and secretion by confocal microscopy and radioimmunoassay, respectively. Our results suggest a possible conservation of ET-1 expression predominantly in the mammalian RPE underlining its importance at this site. Additionally, our results suggest that constitutive ET-1 secretion is predominantly towards the basolateral side in cultured RPE possibly allowing ET-1 to activate its receptors located in the choroidal blood vessels and regulate retinal and choroidal blood flow.
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