Kinetic parameters for mirtazapine-8-hydroxylation, mirtazapine-N-demethylation, and mirtazapine-N-oxidation by human liver microsomes
| Mirtazapine-8-hydroxylation (Michaelis-Menten Equation) | Mirtazapine-N-demethylation (Hill Equation) | Mirtazapine-N-oxidation (Michaelis-Menten or Hill Equation) | ||||||
|---|---|---|---|---|---|---|---|---|
| Km1-a | Vmax1-b | Km | Vmax | a1-c | Km | Vmax | a | |
| HL 01 | 142 | 0.26 | 290 | 1.06 | 1.44 | 329 | 0.25 | 1.46 |
| HL 02 | 115 | 0.30 | 239 | 1.56 | 1.11 | 693 | 0.87 | N.A. |
| HL 03 | 194 | 0.91 | 232 | 2.10 | 1.26 | 359 | 0.69 | 1.28 |
| HL 04 | 92 | 0.38 | 210 | 1.23 | 1.31 | 913 | 0.75 | N.A. |
| Mean (S.D.)1-d | 136 (44) | 0.46 (0.30) | 242 (34) | 1.49 (0.46) | 1.28 (0.14) | 570 (281) | 0.64 (0.27) | |
N.A., not applicable; data consistent with the Michaelis-Menten equation.
↵1-a Km (in μM) represents Michaelis-Menten constant; equals the substrate concentration at 50% of Vmax.
↵1-b Vmax (in nmol/mg of protein/min) represents maximal reaction velocity.
↵1-c a represents Hill coefficient for cooperative substrate binding; if a is given, data was consistent with the Hill equation.
↵1-d Mean (S.D.) represents arithmetic mean of four livers, standard deviation in parentheses.