Cytochrome P450-dependent
metabolism of prochiral PCB 51 and PCB
102 to mono- and dihydroxylated metabolites is cytochrome P450 isoform
and species dependent (analyzed as the corresponding methylated derivatives).
The relative levels of hydroxylated metabolites of (A1) PCB 51 and
(A2) PCB 102 differ between incubations with microsomal preparations
from rats pretreated with inducers of different P450 enzymes. Moreover,
relative levels of hydroxylated metabolites of (B1) PCB 51 and (B2)
PCB 102 vary between incubations with liver microsomes obtained from
different species. Levels of all OH-PCB metabolites were determined
after methylation with diazomethane and are expressed relative to
the internal standard because no authentic standards of the metabolites
were available. Data are presented as mean ± standard deviation
(n = 3 incubations per microsomal preparation; n = 2 for OH-PCB 102 hamster microsomal preparation incubations).
Abbreviations of inducers: BNF, β-naphthoflavone; CFA, clofibric
acid; DEX, dexamethasone; INH, isoniazid; PB, phenobarbital. ND: below
the relative detection limit.