TABLE 1

Effect of various compounds on MTX uptake mediated by hPCFT/HCP1 stably expressed in HEK293 cells

The uptake of [3H]MTX (10 nM) was evaluated at 37°C and pH 5.5 for 1 min in hPCFT/HCP1-transfected cells and mock cells, and the hPCFT/HCP1-specific uptake was calculated by subtracting the uptake in the latter from that in the former. The Km and Vmax for MTX transport were 3.67 ± 0.38 μM and 245.4 ± 19.1 pmol/min/mg protein, respectively, as the computer-fitted parameters with S.E. The uptake rate for control was 0.63 pmol/min/mg protein. Data are represented as the mean ± S.E. (n = 4).

Inhibitor
Concentration
Uptake Rate
mM % Control
Acetylsalicylate 0.2 92.1 ± 4.2
Aurothiomalate 0.2 99.2 ± 4.2
Azathioprine 0.2 96.1 ± 1.3
Dexamethazone 0.2 99.0 ± 1.7
Diclofenac 0.2 63.7 ± 4.8*
Flufenamate 0.2 92.7 ± 6.6
Flurbiprofen 0.2 97.4 ± 3.5
Ibuprofen 0.2 92.8 ± 4.0
Indomethacin 0.2 48.7 ± 1.6*
Ketoprofen 0.2 98.9 ± 4.3
Loxoprofen 0.2 102.8 ± 4.7
Mefenamate 0.2 101.7 ± 7.3
Naproxen 0.2 93.7 ± 3.1
Phenylbutazone 0.2 94.1 ± 3.7
Prednisolone 0.2 96.7 ± 1.9
Prednisone 0.2 100.9 ± 2.1
Salicylamide 0.2 98.0 ± 2.7
Salicylate 2 82.0 ± 2.5
Sulfasalazine
0.2
18.6 ± 2.1*

  • ↵* Significantly different from the value for control at p < 0.05.