Figure 1. Inhibitory effect of BI01383298 on NaCT-mediated citrate uptake in HepG2 cells.

(A) HepG2 cells were co-incubated with BI01383298 and [¹⁴C]-citrate. Uptake of [¹⁴C]-citrate was measured for 30 min in NaCl buffer, pH 7.5, either without (●) or with 10 mM LiCl (○) with increasing concentrations of BI01383298. (B) HepG2 cells were first preincubated with increasing concentrations of BI0138298 in NaCl buffer, pH 7.5, either without (●) or with 10 mM LiCl buffer (○) for 30 min, and then uptake of [¹⁴C]-citrate was measured for 30 min with the same respective preincubation buffer. In this case, the inhibitor was present at different concentrations both during preincubation as well as during uptake. The uptake values were markedly higher when measured in the presence of Li⁺ than in the absence of Li⁺ as expected of human NaCT. The concentration of citrate was 7.0 µM for the uptake assay in the absence of Li⁺, and 3.5 µM for the uptake assay in the presence of Li⁺. Data (means ± S.D.) are presented as percent of the respective control uptake in each case.