Characterization of a rat retinal endothelial cell culture and the expression of P-glycoprotein in brain and retinal endothelium in vitro.

Retinal vascular endothelia form one aspect of the blood-retinal barrier and, like the blood-brain barrier, control the passage of molecules and cells into the parenchyma. To facilitate comparative in vitro studies, rat retinal endothelial cells have been cultured and characterised. Using immunocytochemical techniques, retinal endothelium was positive for von Willebrand's factor, tight junction-associated polypeptide (ZO-1) and the transferrin receptor. The cells also expressed high-affinity uptake of acetylated low-density lipoprotein. Using the monoclonal antibodies JSB-1 and C219, the product of the multidrug resistance gene, P-glycoprotein, was found to be expressed on primary cultures of both brain and retinal endothelium.