TABLE 2

IC50 values of various diuretics for organic anion uptake mediated by hOAT1, hOAT2, hOAT3, and hOAT4

S2 hOAT1, S2 hOAT2, S2 hOAT3, and S2 hOAT4 were incubated in a solution containing either 5 μM [14C]PAH (hOAT1), 50 nM [3H] PGF (hOAT2), or 50 nM [3H]ES (hOAT3 and hOAT4) in the absence or presence of various concentrations of diuretics for 2 min (hOAT1, hOAT3, and hOAT4) or 20 s (hOAT2). Each value represents the mean ± S.E. of eight monolayers from two separate experiments.


Diuretics

hOAT1

hOAT2

hOAT3

hOAT4
μM
Thiazide
Chlorothiazide 3.78 ± 0.41 2205 ± 143 65.3 ± 4.83 2632 ± 132
Cyclothiazide 84.3 ± 7.32 39.2 ± 4.10 27.9 ± 2.12 5000>
Hydrochlorothiazide 67.3 ± 5.32 1023 ± 53.2 942 ± 76.5 5000>
Trichloromethiazide 19.2 ± 1.12 1220 ± 101 71.2 ± 4.32 1505 ± 98.3
Loop diuretic
Bumetanide 7.60 ± 0.58 77.5 ± 5.38 0.75 ± 0.07 348 ± 23.2
Ethacrynic acid 29.6 ± 1.63 121 ± 9.83 0.58 ± 0.08 8.76 ± 0.91
Furosemide 18.0 ± 1.10 603 ± 46.3 7.31 ± 0.81 44.5 ± 2.53
Carbonic anhydrase inhibitor
Acetazolamide 75.0 ± 6.52 5000> 816 ± 67.3 425 ± 39.3
Methazolamide
438 ± 32.1
5000>
97.5 ± 9.84
5000>