Known P-gp substrates demonstrating no effect or a slight modulatory effect on the BL-AP Papp of [3H]paclitaxel, [3H]vinblastine, and [3H]digoxin in MDCK-MDR1 monolayers a
Compound | Concentration | [3H]Paclitaxel BL-AP Papp | [3H]Vinblastine BL-AP Papp | [3H]Digoxin BL-AP Papp |
|---|---|---|---|---|
| μM | % of control | |||
| Colchicine | 10 | 104.3 ± 3.3 | 100.0 ± 11.8 | 102.5 ± 3.5 |
| 100 | 100.0 ± 8.1 | 87.0 ± 2.0* | 93.5 ± 4.9 | |
| Cortisol | 10 | 97.1 ± 5.0 | 112.4 ± 19.9 | 97.0 ± 12.7 |
| 100 | 95.9 ± 3.2 | 108.6 ± 12.8 | 114.9 ± 14.5 | |
| Dexamethasone | 10 | 88.8 ± 13.5 | 98.0 ± 5.3 | 110.5 ± 12.9 |
| 100 | 93.7 ± 6.0 | 114.2 ± 7.6 | 119.3 ± 7.6* | |
| Etoposide | 10 | 100.8 ± 10.8 | 97.3 ± 8.7 | 94.6 ± 15.2 |
| 100 | 116.8 ± 13.2 | 99.1 ± 7.0 | 104.1 ± 14.9 | |
| Trimethoprim | 10 | 109.5 ± 18.7 | 97.8 ± 4.1 | 96.5 ± 5.0 |
| 100 | 119.2 ± 12.1 | 103.2 ± 3.2 | 112.5 ± 1.3** | |
| Probenecidb | 10 | 83.3 ± 5.8 | 98.0 ± 4.3 | 106.5 ± 15.3 |
|
| 100 | 92.0 ± 11.6 | 119.7 ± 71.0 | 92.0 ± 12.7 |
↵ a Experimental Papp (×10-6 cm/s) was calculated as percentage Papp in control monolayers over the course of a 90-min experiment (n = 3-9; *, p < 0.05; **, p < 0.01).
↵ b MRP2 inhibitor included as a negative control (Horikawa et al., 2002).