Fig. 4.
pH dependence of intracellular [3H]chloroquine accumulation (a) and transcellular chloroquine transport from the basal to the apical compartment (b) by monolayers of MDCK-vector control (○) and MDCK-OCT2-MATE1 (•) cells. [3H]chloroquine (0.1 μM) was added to the basal compartment. The pH in the apical compartment was adjusted to 6.0, 6.4, 6.7, 7.0, 7.3, or 7.8. The pH in the basal compartment was 7.3 in all experiments. Data are shown as the mean ± SD. Data were analyzed by one-way ANOVA followed by Bonferroni's posttest (comparison of uptake or transcellular transport in OCT2-MATE1-double-transfected MDCK cells at a given apical pH with the respective control). *, P < 0.05; ***, P < 0.001.