Metabolic activity of 1′-hydroxytriazolam without or with gefitinib in liver and intestinal microsomes
| Metabolic Activity 1′-OH Triazolam | |||
|---|---|---|---|
| Without Gefitinib | With Gefitinib | ||
| pmol/min per milligram of protein | |||
| Liver microsomes | uPA/SCID mice | 1670 ± 151 | 1250 ± 142* |
| Cyp3a KO/uPA/SCID mice | 20.7 ± 3.49††† | 23.5 ± 6.23 | |
| Cyp3a KO chimeric mice | 293 ± 120†††, ‡ | 699 ± 285 | |
| PXB-mice | 413 ± 30.3†††, ‡‡ | 617 ± 39.0** | |
| Humans | 385 ± 5.29 | 946 ± 10.2*** | |
| Intestinal microsomes | uPA/SCID mice | 11.5 ± 11.9 | 11.6 ± 11.7 |
| Cyp3a KO/uPA/SCID mice | ND | ND | |
| Cyp3a KO chimeric mice | ND | ND | |
| PXB-mice | 5.94 ± 10.1 | 5.71 ± 9.69 | |
No mark, not significant; ND, not detected.
* P < 0.05, **P < 0.01, ***P < 0.001 versus the corresponding in the absence of gefitinib. Statistical differences in four mice groups in the absence of gefitinib were determined using one-way analysis of variance followed by Tukey’s test. †††P < 0.001 versus uPA/SCID mice; ‡P < 0.05 and ‡‡P < 0.01 versus Cyp3a KO/uPA/SCID mice.
Triazolam 1′ -hydroxylation in liver and intestinal microsomes were determined using LC-MS/MS. Triazolam (50 μM) was incubated in liver (0.5 mg/ml) and intestinal (1 mg/ml) microsomes without or with gefitinib (12.5 μM) at 37°C for 20 minutes. Data are shown as mean ± S.D. obtained from three male mice or triplicate incubations in human liver microsomes. Statistical differences in the presence or absence of gefitinib were determined by t test.