Table 2.

Inhibition of ATP-dependent MRP5-mediated uptake of 5-FdUMP

CompoundEC50 (mmol/L)
5-FdUMP1.69 ± 0.30
dUMP9.45 ± 0.18
5-FUdR0.46 ± 0.01
Methotrexate0.78 ± 0.23
Pemetrexed2.11 ± 0.38
Cyclic guanosine 3′,5′-monophosphate0.96 ± 0.07
Trequinsin0.58 ± 0.26
Sildenafil0.58 ± 0.09
Zaprinast0.020 ± 0.006
Probenecid0.07 ± 0.02
MK5710.017 ± 0.003
Glybenclamide0.015 ± 0.009
NPPB0.002 ± 0.001
  • NOTE: The uptake of 250 μmol/L [3H]5-FdUMP was measured at 37°C for 40 minutes in the presence of increasing concentrations up to 10 mmol/L of the indicated test compound. The effective concentration that gave 50% inhibition over the dose range (EC50) is listed below. Values are the mean ± SE of two to three independent experiments measured in triplicate.