P450 ± b53-a | Metabolites | |
---|---|---|
Mono-OH-M | Bis-OH-M | |
nmol/20 min/nmol P450 | ||
CYP2C9 −b 5 | 22 ± 13-a | ND |
CYP2C9 +b 5 | 9 ± 2** | ND |
CYP2C18 − b 5 | 57 ± 6 | 38 ± 5 |
CYP2C18 + b 5 | 81 ± 1* | 65 ± 4* |
CYP2C19 − b 5 | 348 ± 29 | 81 ± 7 |
CYP2C19 + b 5 | 362 ± 25 | 25 ± 1** |
CYP2D6 − b 5 | ND | ND |
CYP2D6 +b 5 | ND | ND |
Methoxychlor (25 μM) was incubated in the presence of P450 (40 nM), reductase (0.8 U/ml), andl-α-dilauroyl-phosphatidylcholine (DLPC; 6 μg/ml) for 20 min at 37°C after a 25-min preincubation period on ice. When included, b5 was present at 160 nM. *,p < 0.05; **, p < 0.01. Indicates the activity in the presence of cytochrome b5 is significantly different than the activity in its absence.
ND, not detected.
↵3-a Values represent the mean ± SEM of three determinations.