Evaluation of hepatic biotransformation of polybrominated diphenyl ethers in the polar bear (Ursus maritimus) ...

• Main Authors: Krieger, Lisa K., Szeitz, András, Bandiera, Stelvio M.
• Format: Text
• Language: English
• Published: The University of British Columbia 2018
• Subjects: Arctic; Ursus maritimus
• Online Access: https://dx.doi.org/10.14288/1.0314928; https://doi.library.ubc.ca/10.14288/1.0314928

Polar bears are at the top of the Arctic marine food chain and are subject to exposure and bioaccumulation of environmental chemicals of concern such as polybrominated diphenyl ethers (PBDEs), which were widely used as flame-retardants. The aim of the present study was to evaluate the in vitro oxidative metabolism of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) and 2,2',4,4',5-pentabrominated diphenyl ether (BDE-99) by polar bear liver microsomes. The identification and quantification of the hydroxy-brominated diphenyl ethers formed were assessed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with archived individual liver microsomes, prepared from fifteen polar bears from northern Canada, produced a total of eleven hydroxylated metabolites, eight of which were identified using authentic standards. The major metabolites were 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether and 5′-hydroxy-2,2'4,4'-tetrabromodiphenyl ether. Incubation of ...