Table 2

Inhibitory effect of various compounds on uptake of [14C]TEA by OCTN1-transfected HEK293 cells

InhibitorConcentrationRelative Uptake
mM % of control
Control100
Choline573.2  ± 3.62-150
Cimetidine150.6  ± 1.72-150
Clonidine170.9  ± 4.72-150
Guanidine589.6  ± 8.3
NMN5101  ± 1.8
Nicotine171.6  ± 3.62-150
Procainamide115.6  ± 0.72-150
Putrescine5111  ± 10.0
Pyrilamine10.0  ± 2.732-150
Spermidine5109  ± 7.2
Spermine5104  ± 7.2
Quinine124.6  ± 1.12-150
Quinidine115.2  ± 2.12-150
TEA118.4  ± 1.32-150
Verapamil18.8  ± 4.22-150
Ofloxacin161.4  ± 5.32-150
Levofloxacin163.6  ± 1.42-150
l-Carnitine132.5  ± 3.32-150
d-Carnitine153.9  ± 0.52-150
Cephaloridine135.7  ± 4.52-150
l-Arginine5111  ± 2.3
l-Lysine593.8  ± 2.5
p-Aminohippuric acid5103  ± 8.4
Benzylpenicillin5113  ± 3.3

Uptake of [14C]TEA (60 μM) was measured for 3 min at 37°C in transport medium (pH 7.4) containing each inhibitor. Each value represents mean ± S.E. of three determinations. Data were obtained by subtraction of uptake by mock-transfected HEK293 cells from that by OCTN1-transfected HEK293 cells.

  • 2-150  Significantly different from the control uptake (p < .05).