Figure 5. Effects of embryonic age and retinal conditioned medium on the permeability of RPE.

The permeability of RPE was calculated from linear regression analysis of the data exemplified in Figure 4. Assays were performed on 3-4 cultures. In growth medium (SF2), there was a 40% decrease in the permeability to HRP between E7 and E10 with no difference for inulin or mannitol. Between E10 and E14, there was a 40% decrease in the permeability to inulin, but only a 15% decrease for mannitol. In E14 retinal conditioned medium (CM), the permeability of each tracer decreased, but the age related differences were eliminated. Error bars represent the standard error. Confidence levels: * p < 0.01; # p < 0.05.