FIGURE 8.
In vitro transport assay to determine the interaction between TP and hepatic transporters. (A,B) Effects of TP on P-gp and MRP2-mediated transports in the vesicular transport (VT) assay. TP was incubated with relative membrane vesicles and substrates at 37°C for 10 min. N-methyl quinidine was used as the positive control. The ATP-dependent transport in the absence of TP was set as 100%. (C–E) Uptake of TP by MRP2 in the VT assay as well as OATP1B1 and OATP1B3 in human embryonic kidney 293 cells. Membrane vesicles or cells were incubated with TP at 37°C for 10 min. E217βG was used as the positive control. Uptake ratio (UR) in the MRP2 vesicles was calculated by the transport activity in the presence of ATP dividing that in the presence of AMP. UR in the OATP-expressing cells was calculated by the transport activity in OATP-expressing cells dividing that in the control cells. Data were presented as means ±SE (n = 3).