Figure 2.

Effect of reduced (GSH) and oxidized (GSSG) glutathione (1 mM) on ³H-MPP⁺ apical uptake (represented as % of the control treatment) by Caco-2 cells. Confluent Caco-2 monolayers were preincubated at 37°C for 3 and 60 min and then incubated with 200 nM ³H-MPP⁺ for 5 min in the presence of H₂O (control) or the tested compounds. each value represents the mean ± SEM (n = 6). *p < 0.05.