Research Article Open Access

In Vitro Metabolism Studies of Polybrominated Diphenyl Ethers Using Rat and Human Liver Microsomes

Shun Wen Cheng1, Kathleen Randall1 and Anne T. Kotchevar1
  • 1 California State University, United States

Abstract

A number of studies have recently reported the bioaccumulation of the commonly used fire retardants, Polybrominated Diphenyl Ethers (PBDEs), in humans and wildlife. Exposure of animals to PBDEs has been shown to result in developmental neurological, reproductive abnormalities and the disruption of endocrine function. Thyroid hormone equilibria was also shown to be altered by PBDE exposure. There is evidence that hydroxylated metabolites of PBDEs are directly involved in some of these adverse effects. Although metabolites of PBDEs have been isolated and characterized during in vivo studies, the identification of metabolites from an in vitro system has been problematic. We investigated the in vitro metabolism of four PBDEs, with varying numbers of bromine atoms, in rat and human liver microsomes. The addition of small amounts of a nonionic surfactant to the reaction mixture was necessary to obtain measurable amounts of metabolites due to the low aqueous solubility of the PBDEs. Using gas chromatography/mass spectroscopy, mono and/or dihydroxylated metabolites were identified from three of the four PBDEs with phenobarbitol- and β-naphthoflavone-induced rat liver microsomes. When using uninduced rat or human liver microsomes, metabolites were found with only one of the PBDEs. The ease of PBDE metabolism appears to be inversely related to the number of bromine atoms on the parent compound.

American Journal of Biochemistry and Biotechnology
Volume 4 No. 3, 2008, 295-303

DOI: https://doi.org/10.3844/ajbbsp.2008.295.303

Submitted On: 18 January 2008 Published On: 30 September 2008

How to Cite: Cheng, S. W., Randall, K. & Kotchevar, A. T. (2008). In Vitro Metabolism Studies of Polybrominated Diphenyl Ethers Using Rat and Human Liver Microsomes. American Journal of Biochemistry and Biotechnology, 4(3), 295-303. https://doi.org/10.3844/ajbbsp.2008.295.303

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Keywords

  • PBDE
  • metabolites
  • GC-MS
  • surfactant
  • solubility