Journal article
Atropselective Disposition of 2,2',3,4',6-Pentachlorobiphenyl (PCB 91) and Identification of Its Metabolites in Mice with Liver-Specific Deletion of Cytochrome P450 Reductase
Chemical research in toxicology, Vol.33(6), pp.1328-1338
08/26/2019
DOI: 10.1021/acs.chemrestox.9b00255
PMCID: PMC7042073
PMID: 31403789
Abstract
Hepatic cytochrome P450 enzymes metabolize chiral polychlorinated biphenyls (PCBs) to hydroxylated metabolites (OH-PCBs). Animal models with impaired metabolism of PCBs are one approach to study how the atropselective oxidation of PCBs to OH-PCBs contributes to toxic outcomes, such as neurodevelopmental disorders, following PCB exposure. We investigated the disposition of PCB 91, a
-substituted PCB congener, in mice with a liver-specific deletion of the cytochrome P450 reductase (
) gene (KO mice). KO mice and wild-type (WT) mice were exposed orally to racemic PCB 91 (30 mg/kg b.w.). Levels and enantiomeric fractions of PCB 91 and its hydroxylated metabolites were determined in tissues 3 days after PCB exposure and in excreta on days 1-3 after PCB exposure. PCB 91, but not OH-PCB levels were higher in KO compared to WT mice. The elevated fat and protein content in the liver of KO mice resulted in the hepatic accumulation of PCB 91. OH-PCBs were detected in blood, liver, and excreta samples of KO and WT mice. 2,2',3,4',6-Pentachlorobiphenyl-5-ol (5-91) was the major metabolite. A considerable percent of the total PCB 91 dose (%TD) was excreted with the feces as 5-91 (23%TD and 31%TD in KO and WT mice, respectively). We tentatively identified glucuronide and sulfate metabolites present in urine samples. The PCB 91 atropisomer eluting first on the chiral column (E
-PCB 91) displayed genotype-dependent atropisomeric enrichment, with a more pronounced atropisomeric enrichment observed in WT compared to KO mice. E
-atropisomers of 5-91 and 2,2',3,4',6-pentachlorobiphenyl-4-ol (4-91) were enriched in blood and liver, irrespective of the genotype; however, the extent of the enrichment of E
-5-91 was genotype dependent. These differences in atropselective disposition are consistent with slower metabolism of PCB 91 in KO compared to WT mice and the accumulation of the parent PCB in the fatty liver of KO mice.
Details
- Title: Subtitle
- Atropselective Disposition of 2,2',3,4',6-Pentachlorobiphenyl (PCB 91) and Identification of Its Metabolites in Mice with Liver-Specific Deletion of Cytochrome P450 Reductase
- Creators
- Xianai WuGuangshu ZhaiJerald L SchnoorHans-Joachim Lehmler
- Resource Type
- Journal article
- Publication Details
- Chemical research in toxicology, Vol.33(6), pp.1328-1338
- DOI
- 10.1021/acs.chemrestox.9b00255
- PMID
- 31403789
- PMCID
- PMC7042073
- NLM abbreviation
- Chem Res Toxicol
- ISSN
- 1520-5010
- eISSN
- 1520-5010
- Publisher
- United States
- Grant note
- P42 ES013661 / NIEHS NIH HHS P30 ES005605 / NIEHS NIH HHS R21 ES027169 / NIEHS NIH HHS
- Language
- English
- Date published
- 08/26/2019
- Academic Unit
- Civil and Environmental Engineering; Occupational and Environmental Health; Iowa Neuroscience Institute; Iowa Superfund Research Program
- Record Identifier
- 9984000921702771
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