Figure 4. Alkaline phosphatase activity assay and levamisole-mediated inhibition.

(A) Alkaline phosphatase activity, (B) monolayer permeability to Lucifer Yellow (Pe^LY) and (C) percentage of endothelial cell death (LDH leakage into the culture medium): determined after 4h of incubation of bovine BCECs with limited BBB functions (Lim. BBB) or re-induced BBB functions (Re-ind. BBB) with different concentrations of levamisole (0 to 5 mM). The extent of cell death in each experimental condition was expressed as percentage of full kill (where the latter corresponded to cells lysed with 9% Triton X-100 (w/v) buffer). The statistical analysis was carried out using PRISM 5 software. The results correspond to the mean ± SEM (N = 3, n = 9 BCEC monolayers per treatment). The significance of between-experiment differences were tested in a two-way analysis of variance, followed by a Bonferroni post hoc test. * p<0.05; *** p<0.001; NS: non-significant.