title: Dietary accumulation, disposition, and metabolism of technical pentabrominated diphenyl ether (de-71) in pregnant mink (Mustela vison) and their offspring.
abstract: Concentrations of polybrominated diphenyl ethers (PBDEs) in humans and wildlife suggest significant bioaccumulation potential in mammals, but no quantitative biomagnification data from controlled experiments are currently available. As part of a larger study examining the effects of PBDEs on mink (Mustela vison) reproduction and development, we examined congener-specific tissue distribution, maternal transfer, biotransformation, and biomagnification of the technical penta-BDE mixture, DE-71, in farmed mink. Adult female mink were fed one of four concentrations of DE-71 (0-2.5 microg/g) in the diet from breeding through gestation and until weaning at 6 weeks postparturition. Parent PBDEs were measured in tissues and excreta of adult mink, kits, and juveniles, whereas hydroxylated PBDEs (OH-PBDEs) were measured in juveniles only. Similar lipid-normalized concentrations of PBDEs were detected in most tissues of adult mink with the exception of brain, in which concentrations were significantly lower. Kits, however, had a higher proportion of PBDEs in brain compared with adults, presumably because of incomplete development of the blood-brain barrier. Maternal transfer favored lower-brominated PBDE congeners, and the bulk of the body burden in kits at weaning resulted from lactational rather than transplacental transfer. Lipid-normalized, whole-body biomagnification factors ranged from 0.5 to 5.2 for the major congeners and were highest for BDEs 47 and 153. Metabolism clearly limited the biomagnification of some PBDEs, and OH-PBDEs were detectable in plasma, liver, and feces. On a mass basis, OH-PBDEs accounted for 28 to 32% of the excreted fraction, indicating metabolism was an important elimination pathway. Further studies are required to understand the mechanisms of PBDE biotransformation.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Si
authors.initials: S
authors.lastname: Zhang
authors.forename: Steve
authors.initials: S
authors.lastname: Bursian
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Martin
authors.forename: Hing Man
authors.initials: HM
authors.lastname: Chan
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D000818:Animals; D004032:Diet; D004785:Environmental Pollutants / Q000493:pharmacokinetics*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers; D018811:Maternal Exposure; D008431:Maternal-Fetal Exchange; D008907:Mink / Q000378:metabolism*; D010647:Phenyl Ethers / Q000493:pharmacokinetics*; D011075:Polybrominated Biphenyls / Q000493:pharmacokinetics*; D011247:Pregnancy; D014018:Tissue Distribution
chemical_list: D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; C086401:pentabromodiphenyl ether