FIG. 5.

Uptake of estradiol-17-β-d-glucuronide and TFV into membrane vesicles derived from insect cells. Addition of ATP, but not AMP, stimulated the uptake of estradiol-17-β-d-glucuronide into MRP2 vesicles (A). No specific increase in the accumulation of TFV was noted in MRP2 vesicles upon addition of ATP (B). While addition of 200 μM MK571 was able to reduce the transport of estradiol-17-β-d-glucuronide to levels observed in the absence of ATP, TFV at a concentration of 50 or 200 μM was unable to inhibit estradiol-17-β-d-glucuronide accumulation (C). Values represent the mean ± standard deviation of two independent experiments performed in duplicate. Statistical significance was assessed by Student's unpaired two-tailed t test assuming equal variance (*, P < 0.05; **, P < 0.01).