(A) and (C) iAs+3 (0, 1, 5, 10, 20, 25, 50 μM) (B) and (D) iAs+3 (25 μM) with UroA (0, 5, 10, 25, 50 μM) were added to the apical compartment of EpiIntestinal 3D microtissues grown on Transwell inserts and incubated at 37 °C for 24 h and 48 h, respectively. FITC-dextran was added to these cells (apical compartment) and incubated for 2 h at 37°C and FITC-dextran levels in the bottom chamber well (basal compartment) was measured. *p < 0.05, **p < 0.01, ***p < 0.001, Statistics performed using one-way ANOVA in GraphPad Prism software. Error bar, mean ± SEM (n=4).