IC50 values for inhibition of radiolabel substrate uptake by purine and pyrimidine substrates
IC50 values are means ± S.D. for ≥3 experiments. Pyrimidines were competed with 50 nM [3H]adenosine; purines were competed with 250 nM [3H]uridine.
| Uptake Inhibition IC50 Values | |||
|---|---|---|---|
| Pyrimidine | IC50 Versus [3H]Adenosine | Purine | IC50 Versus [3H]Uridine |
| µM | µM | ||
| Uracil | 2833 ± 243 | Adenine | 306 ± 19 |
| Uridine | 400 ± 152 | Adenosine | 190 ± 2.5 |
| Thymine | 1142 ± 185 | Hypoxanthine | 53 ± 1.65 |
| Thymidine | 91.3 ± 38 | Inosine | 3.7 ± 0.1 |
| Cytosine | 9697 ± 455 | Guanine | 1142 ± 44 |
| Cytidine | 26726 ± 4116 | Guanosine | 21.3 ± 0.6 |
| Xanthine | 979 ± 13 | ||
| Xanthosine | 626 ± 17 | ||