Effect of KZ on catechol formation from 4-OH-tam by human liver microsomes
| KZ | Methylated catechol | % of Control |
|---|---|---|
| μM | nmol/mg protein | |
| 0 | 6.84 ± 0.25 | 100 |
| 0.1 | 5.18 ± 0.17 (p ≤ .0002) | 76 |
| 0.5 | 5.43 ± 0.42 (p ≤ .0025) | 79 |
| 1.0 | 9.64 ± 0.58 (p ≤ .0003) | 141 |
| 5.0 | 26.71 ± 1.71 (p ≤ .0001) | 391 |
Human liver microsomes (IIAM donor # 225; 10μg), 4-OH-tam (25 μM), DTT (50 μM), COMT (120 U), SAM (200 μM/1 μCi), and NADPH-regenerating system were incubated in a final volume of 0.4 ml for 30 min at 37°C. Values represent a mean ± S.D. of triplicate measurements.
Note: Liver #225 contained high level of CYP3A (8.0 nmol 6β-OH-testosterone/mg protein/min) and low level of 2D6 (261 pmol dextromethorphan-O-demethylation/mg protein/min) activity.