Apparent kinetic parameters for metabolism of phenacetin, 7EC, and coumarin in dog recombinant CYP2A13, CYP2A25, and pooled dog liver microsomes (DLM)
Incubations with 7EC were performed in triplicates, whereas other substrates were performed in duplicates. Data are presented as mean ± S.E. of parameter fit using one-enzyme Michaelis-Menten model.
| Enzyme | Substrate | Km | Vmax | CLint (Vmax/Km) | Vmax | CLint (Vmax/Km) |
|---|---|---|---|---|---|---|
| μM | pmol/min/pmol | μl/min/pmol | pmol/min/mg | μl/min/mg | ||
| CYP2A13 | Phenacetin | 3.9 ± 0.7 | 3.6 ± 0.1 | 0.92 | ||
| 7EC | 4.8 ± 2.5 | 47 ± 28 | 9.8 | |||
| Coumarin | 2.1 ± 0.3 | 19 ± 1 | 9.1 | |||
| CYP2A25 | 7EC | 150 ± 10 | 8.4 ± 0.3 | 0.056 | ||
| DLM | Phenacetin | 9.6 ± 2.7 | 440 ± 30 | 46 | ||
| 7EC | 7.5 ± 1.3 | 2900 ± 200 | 380 | |||
| Coumarin | 0.75 ± 0.42 | 310 ± 10 | 4100 |