Kinetic analysis of diazepam 3-hydroxylation and N-demethylation and testosterone 6β-hydroxylation in B-lymphoblastoid microsomes expressing CYP3A4 and CPR
| Hill Equation | Two-Site Model | ||||||
|---|---|---|---|---|---|---|---|
| Vmax | S50 | n | CLmax | Vmax | Ks | α | |
| pmol/min/pmol CYP | μM | μl/min/pmol CYP | pmol/min/pmol CYP | μM | |||
| Diazepam | |||||||
| 3HDZ | 30 (1) | 140 (8) | 1.42 (0.04) | 0.12 | 28 (1) | 421 (33) | 0.09 (0.02) |
| NDZ | 2.7 (0.5) | 152 (56) | 1.20 (0.14) | 0.011 | 2.5 (0.3) | 252 (40) | 0.28 (0.18) |
| Testosterone | |||||||
| 6β-HTS | 19 (0.5) | 51 (3) | 1.45 (0.05) | 0.20 | 20 (0.3) | 129 (14) | 0.17 (0.04) |
The kinetic parameters were determined using the Hill equation (eq. 1) and a two-site model (eq. 3) using GRAFIT v3.0 (Erithacus Software Ltd). Values in parentheses represent standard error values.