Figure 6.

Efflux of [³H]-tenofovir by HEK cells expressing the wild type MRP4 and its variants. HEK293 cells stably expressing empty pcDNA5/FRT vector, the MRP4 wild type (reference), or its variants were preincubated with 1 μM [³H]-tenofovir disoproxil for 2 h under ATP-depleting conditions. After washing, the cells were supplemented with complete DMEM, and extracellular concentrations of tenofovir were determined at 0, 30, and 90 min. Data are mean ± standard deviation of triplicate determinations from one experiment and are representative of multiple experiments.