Table 1. Cis-inhibition of TEA transport by hMATE1
Compound mM Transport, % of control
Mock control 18.6 ± 1.2
No addition (Control) 100.0 ± 1.9
Cimetidine 0.01 55.1 ± 7.4**
0.1 26.4 ± 8.7**
Quinidine 0.01 47.0 ± 2.1**
0.05 22.8 ± 8.9**
0.1 10.2 ± 4.2**
Procainamide 0.1 69.5 ± 0.8**
Verapamil 0.1 24.7 ± 7.4**
Guanidine 0.5 94.6 ± 7.6
Carnitine 5 103.4 ± 6.4
TEA 5 19.0 ± 1.8**
MPP 0.1 73.4 ± 8.4*
5 11.2 ± 0.3**
Nicotine 0.1 70.4 ± 5.0*
5 23.1 ± 4.3**
Serotonin 0.1 83.5 ± 8.0*
Rhodamine123 0.01 22.5 ± 6.4**
NMN 1 94.7 ± 1.9
Choline 5 69.6 ± 4.1**
Corticosterone 0.1 26.6 ± 6.7**
Lactate 10 103.1 ± 8.8
Succinate 10 106.6 ± 4.2
Salicylate 10 98.2 ± 4.8
PAH 5 108.4 ± 2.7
Probenecid 1 106.9 ± 7.9
Urate 1 102.4 ± 2.7
  • Cis-inhibition of TEA uptake revealed the substrate specificity of MATE1. The uptake of 50 μM radiolabeled TEA by hMATE1-expressing HEK293 cells at pH 8.0 was determined after 20 min in the presence or absence of the listed compounds at the indicated concentrations. The values were expressed as percentages of radiolabeled TEA uptake under control conditions (no test substance added). NMN, N-methyl nicotinamide; PAH, p-aminohippurate. Data are means ± SEM, n = 3-9. *, P < 0.05; **, P < 0.001, compared with the uptake in the absence of the compound (control).