Effects of inhibitory antibodies on the hydroxylation of emodin in rat liver microsomes
| Microsomal Preparation and Treatment4-a | Activity4-b | |
|---|---|---|
| Formation of ω-Hydroxyemodin | Formation of 2-Hydroxyemodin | |
| % of control | ||
| PB-pretreated male rats, +anti-rat cytochrome P4502B1/2 antibody | 85 | 70 |
| MC-pretreated male rats, +anti-rat cytochrome P4501A1 antibody | 100 | 80 ± 6 |
| MC-pretreated male rats, +anti-rat cytochrome P4501A1/2 antibody | 100 | 51 ± 11 |
↵4-a Incubations were performed as described inMaterials and Methods, with the indicated variation and with 500 μM emodin. PB, phenobarbital; MC, 3-methylcholanthrene.
↵4-b Rates of formation of ω-hydroxyemodin and 2-hydroxyemodin were determined to be 23 ± 5 and 2.6 ± 0.5 nmol/min/mg protein, respectively, in liver microsomes from untreated rats and 36 ± 1 and 2.0 ± 0.3 nmol/min/mg protein, respectively, in liver microsomes from phenobarbital-pretreated rats; rates of formation of ω-hydroxyemodin and 2-hydroxyemodin in liver microsomes from 3-methylcholanthrene-pretreated rats were determined to be 19 ± 3 and 9 ± 1 nmol/min/mg protein, respectively (all given as mean ± SD, N = 3).