Comparative kinetic parameters for human OAT and rat Oat transporters mediating in vitro transport of tanshinol
Values represent the mean ± S.D.(n = 3).
| Transporter | Km | Vmax | CLint | IC50 | |
|---|---|---|---|---|---|
| Probenecid against Tanshinol | Tanshinol against Positive Substrate | ||||
| μM | pmol/mg protein/min | μl/mg protein/min | μM | ||
| Positive substrate (in parentheses) | |||||
| Human | |||||
| OAT1 (Para-aminohippuric acid) | 60.3 ± 5.5 | 1379 ± 39 | 22.9 | ― | 98 ± 7 |
| OAT2 (Prostaglandin F2α) | 45.5 ± 12.4 | 360 ± 54 | 7.91 | ― | 1528 ± 51 |
| OAT3 (Estrone-3-sulfate) | 28.1 ± 3.7 | 73.1 ± 4.4 | 2.60 | ― | 2803 ± 150 |
| OAT4 (Estrone-3-sulfate) | 49.9 ± 5.3 | 232 ± 9 | 4.64 | ― | 4079 ± 410 |
| Rat | |||||
| Oat1 (Para-aminohippuric acid) | 102 ± 17 | 2299 ± 138 | 22.5 | ― | ― |
| Oat2 (Prostaglandin F2α) | 27.0 ± 10.3 | 511 ± 113 | 18.9 | ― | ― |
| Oat3 (Estrone-3-sulfate) | 17.1 ± 4.1 | 161 ± 11 | 9.41 | ― | ― |
| Tanshinol as substrate | |||||
| Human | |||||
| OAT1 | 121 ± 13 | 1414 ± 40 | 35.4 | 4.57 ± 0.30 | ― |
| OAT2 | 859 ± 70 | 4555 ± 146 | 5.30 | 393 ± 118 | ― |
| OAT3 | 1888 ± 395 | 182 ± 17 | 0.0963 | 10.9 ± 2.9 | ― |
| OAT4 | 1880 ± 555 | 169 ± 22 | 0.0899 | 134 ± 50 | ― |
| Rat | |||||
| Oat1 | 117 ± 24 | 599 ± 35 | 5.12 | 6.19 ± 0.18 | ― |
| Oat2 | 1207 ± 470 | 1751 ± 297 | 1.45 | 108 ± 31 | ― |
| Oat3 | 1498 ± 225 | 1030 ± 63 | 0.688 | 9.51 ± 1.52 | ― |