β-Naphthoflavone- and self-induced metabolism of 3,3',4,4'-tetrachlorobiphenyl in hepatic microsomes of the male, pregnant female and foetal rat

Article abstract of DOI:10.3109/00498259509061849

1. The in vitro metabolism of 3,3',4,4'-tetrachloro-[¹⁴C]-biphenyl ([¹⁴C]-TCB) by hepatic microsomes from the Wistar rat was investigated with liver microsomes from the male, pregnant female and foetus. 2. Three hydroxylated metabolites (4-OH-3,3',4,5'-tetrachlorobiphenyl, 5-OH-3,3',4,4'-tetrachlorobiphenyl, and 6-OH-3,3',4,4'-tetrachlorobiphenyl) were identified by hplc and gc-ms after incubations of liver microsomes from the β-naphthoflavone-pretreated male rat and TCB-treated pregnant rat. No metabolites of [¹⁴C]-TCB were found after incubation with foetal liver microsomes from dams pretreated with [¹⁴C]-TCB. The results indicate that the in vivo accumulation of 4-OH-tetraCB in the foetal compartment is probably due to transplacental transport rather than the formation of this metabolite in the foetus. 3. Pretreatment of the male rat with β-naphthoflavone substantially induced the formation of hydroxylated metabolites, but pretreatment with phenobarbital and dexamethasone was without effect. Based on in vitro incubations of liver microsomes from the β-naphthoflavone pretreated male rat, an apparent K(m) and V(max) of 4.5 μM and 240 pmol/mg protein/min respectively was determined for the metabolism of [¹⁴C]-TCB. The formation of phenolic metabolites of [¹⁴C]-TCB was most likely dependent on P4501A induction.

Full text of DOI:10.3109/00498259509061849

Xenobiotica
the fate of foreign compounds in biological systems
ISSN: 0049-8254 (Print) 1366-5928 (Online) Journal homepage: http://www.tandfonline.com/loi/ixen20
β-Naphthoflavone- and self-induced metabolism
of 3,3′,4,4′-tetrachlorobiphenyl in hepatic
microsomes of the male, pregnant female and
foetal rat
D. C. Morse, P. J. Van Bladeren, E. Klasson Wehler & A. Brouwer
To cite this article: D. C. Morse, P. J. Van Bladeren, E. Klasson Wehler & A. Brouwer (1995)
β-Naphthoflavone- and self-induced metabolism of 3,3′,4,4′-tetrachlorobiphenyl in hepatic
microsomes of the male, pregnant female and foetal rat, Xenobiotica, 25:3, 245-260
To link to this article: http://dx.doi.org/10.3109/00498259509061849
Published online: 27 Aug 2009.
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Date: 05 November 2015, At: 17:09