Metabolism of estradiol-17β-glucuronide using various P450 preparations
Incubations were performed using 1 μM P450 liver microsomes or 0.5 μM expressed P450 (n = number of independent determinations) and 100 μM substrate for the indicated times in the presence of an NADPH-generating system.
Microsomes | Incubation Time | Turnover Values |
|---|---|---|
| min | nmol · min-1 · nmol-1 P450 | |
| Human male (n = 7) | 30 | 0.17 ± 0.03 |
| 60 | 0.12 ± 0.04 | |
| Human female (n = 4) | 30 | 0.33 ± 0.05 |
| 60 | 0.25 ± 0.09 | |
| Rat UT (n = 3) | 60 | 0.0007 |
| Rat Dex (n = 2) | 60 | 0.0007 |
| Rat PB (n = 2) | 60 | N.D. |
| Dog | 60 | N.D. |
| Monkey | 60 | Traces |
| Mice | 60 | N.D. |
| Bactosome-expressed P450 | ||
| 2A6 (n = 2) | 30 | N.D. |
| 2C8 (n = 4) | 30 | 0.19 ± 0.02 |
| 2C9 (n = 2) | 30 | N.D. |
| 2C19 (n = 2) | 30 | N.D. |
| 3A4 (n = 3) | 30 | N.D. |
| 3A7 (n = 2) | 30 | 0.04 |
| Yeast-expressed | ||
| 2C8 (n = 3) | 30 | 0.61 ± 0.05 |
| 2C8 R 241A (n = 2) | 30 | N.D. |
| 3A4 (n = 2) | 30 | N.D. |
UT, untreated; N.D., not detected. `Traces' indicates that the XOH E2 metabolite was observable but not quantifiable.