Figure 4.
Effect of protonophores on pyridoxine uptake by SLC19A2 and SLC19A3 stably expressed in MDCKII cells. The specific uptake of [3H]pyridoxine (5 nm) by SLC19A2 (A) and SLC19A3 (B) was evaluated for 3 min at pH 5.5 and 37 °C in the presence of a protonophore (100 μm), or in its absence (control), after pretreatment for 5 min with, or without, the protonophore under the same condition. The control values were 47.5 and 87.8 fmol/min/mg of protein, for SLC19A2 and SLC19A3, respectively. Data are presented as the mean ± S.D. (n = 4). *, p < 0.05 compared with control, as assessed by ANOVA followed by Dunnett's test.