Table 2.

Effects of glucuronide and glutathione conjugates on MRP4-mediated, ATP-dependent, [3H]MTX transporta

CompoundConcentration (μM)[3H]MTX Uptake (% of Control)
a Membrane vesicles from Sf9-MRP4 cells were incubated with 0.1 μM [3]HMTX for 10 min at 37°C, in the absence (control) or presence of various compounds. Net ATP-dependent uptake was expressed as a percentage of control uptake. Data represent mean ± SEM values of three to six determinations. MTX, methotrexate; DNP-SG, S-(2,4-dinitrophenyl)-glutathione; NAc-DNP-Cys, N-acetyl (2,4,-dinitrophenyl)-cysteine.
b P < 0.05.
c P < 0.01 (ANOVA with Bonferroni’s correction).
No inhibitor100
DNP-SG186 ± 7b
1057 ± 8c
1003 ± 4c
NAc-DNP-Cys161 ± 4c
1047 ± 8c
10029 ± 3c
Leukotriene C41102 ± 4
α-Naphthyl-β-d-glucuronide1075 ± 2c
10025 ± 3c
100018 ± 1c
p-Nitrophenyl-β-d-glucuronide1088 ± 4b
10075 ± 2c
100025 ± 5c
Estradiol-17β-d-glucuronide10075 ± 2c