Enzyme activities of biological samples and effects of typical inhibitors
Each value represents the mean ± S.D. (n = 3).
| Marker Enzyme | Enzyme Source | Probe Substrate | Inhibitor | Enzyme Activity |
|---|---|---|---|---|
| CYP2A6 (pmol/min/pmol of P450) | cDNA-expressed | Coumarin | 7.1 ± 0.1 | |
| +TCP (10 μM) | 0.7 ± 0.2 | |||
| CYP2A6 (pmol/min/mg) | Microsomes | Coumarin | 424.0 ± 30.3 | |
| +TCP (10 μM) | 12.0 ± 1.6 | |||
| CYP2A6 (pmol/min/mg) | S9 | Coumarin | 262.7 ± 9.7 | |
| +TCP (10 μM) | 11.4 ± 0.3 | |||
| TPase (nmol/min) | Purified TPase | Thymidine | 6.6 ± 0.3 | |
| +TPI (10 μM) | N.D. | |||
| TPase (nmol/min/mg) | Cytosol | Thymidine | 9.0 ± 0.3 | |
| +TPI (10 μM) | N.D. | |||
| TPase (nmol/min/mg) | S9 | Thymidine | 5.5 ± 0.7 | |
| +TPI (10 μM) | N.D. | |||
| ALDH (nmol/min/mg) | Cytosol | Acetaldehyde | 5.8 ± 0.8 | |
| +Disulfiram (100 μM) | 0.4 ± 0.4 | |||
| ALH (nmol/min/mg) | Cytosol | Ethanol | 18.0 ± 1.5 | |
| +4-Methylpyrazole (100 μM) | 3.1 ± 0.7 | |||
| ALO (nmol/min/mg) | Cytosol | Phenanthridine | 2.8 ± 0.2 | |
| +Menadione (100 μM) | 0.2 ± 0.1 |
ALDH, aldehyde dehydrogenase; ALH, alcohol dehydrogenase; ALO, aldehyde oxidase; cDNA-expressed, cDNA-expressed CYP2A6; microsomes, human liver microsomes; S9, human liver S9; cytosol, human liver cytosol; N.D., not detected.