Table 1.
Metabolism of nicotine, cotinine, and aminoketone by human liver microsomes
| Experiment | Reaction mixtures containing human
liver microsomes and
|
Products (nmol)
|
||||||
|---|---|---|---|---|---|---|---|---|
| Nicotine | Cotinine | Aminoketone | Cytosol | NADPH | Keto acid | Hydroxy acid | Cotinine | |
| 1 | + | − | − | + | + | 0.51 | ND | 8.3 |
| 2 | + | − | − | − | + | 0.36 | ND | ND |
| 3 | + | − | − | − | − | ND | ND | ND |
| 4 | − | + | − | + | + | ND | ND | 13 |
| 5 | − | + | − | − | + | ND | ND | 13 |
| 6 | − | + | − | − | − | ND | ND | 14 |
| 7 | − | − | + | + | + | 12 | 0.44 | ND |
| 8 | − | − | + | − | + | 6.0 | ND | ND |
| 9 | − | − | + | − | − | 6.5 | ND | ND |
| 10 | − | − | − | + | + | ND | ND | ND |
| 11 | − | − | − | − | + | ND | ND | ND |
| 12 | − | − | − | − | − | ND | ND | ND |
Incubation mixtures contained nicotine (61.7 μM), cotinine (31.8 μM), or aminoketone (21.5 μM), human liver microsomes, and cofactors in a total volume of 0.5 ml, as described in Materials and Methods. Reactions were carried out at 37°C for 30 min; keto acid, hydroxy acid, and cotinine were quantified as described in Materials and Methods. ND, not detected.