Fig. 7. Reversibility of disruption of epithelial barrier by RA.

RCE1(5T5) corneal epithelial cells were grown as described (see Materials and Methods). One day after confluence, 3–5 layered epithelia were incubated with medium containing 0.1, 1.0 or 10 µM RA for 48 hours (arrows). Then, cells were rinsed thrice with PBS and changed to basal medium. TER was determined every day for each cell culture condition beginning at the day in which cells were changed to medium containing the retinoid. As shown, RA disrupted epithelial barrier in a reversible manner, with the highest effect and the slower recovery in cell cultures treated with 10 µM RA. Results correspond to three duplicate experiments; asterisks indicate significant differences (P≤0.05).