title: Exposure to polybrominated diphenyl ethers (PBDEs): changes in thyroid, vitamin A, glutathione homeostasis, and oxidative stress in American kestrels (Falco sparverius).
abstract: Polybrominated diphenyl ethers (PBDEs), a class of additive flame retardants, are temporally increasing in wildlife tissues and capable of disrupting normal endocrine function. We determined whether in ovo and post-hatch exposure of captive American kestrels (Falco sparverius) to environmentally relevant PBDEs alter thyroid, retinol, and oxidative stress measures. Control eggs were injected with safflower oil and subsequent nestlings fed the same vehicle; dosed eggs received PBDE congeners (BDE-47, -99, -100, -153), which mainly comprise the Penta-BDE commercial mixture, dissolved in safflower oil at concentrations (1500 ng/g total [Sigma] PBDEs) approximating those in Great Lakes gull eggs. Nestlings hatching from dosed eggs were orally exposed for 29 days to variable SigmaPBDE concentrations that are similar to levels reported in tissues of Great Lakes trout (100 ng/g). Treatment kestrels had lower plasma thyroxine (T(4)), plasma retinol, and hepatic retinol and retinyl palmitate concentrations, but unaltered triiodothyronine (T(3)) concentrations and thyroid glandular structure. BDE-47, -100, and -99 were negatively associated with plasma T(4), plasma retinol (BDE-100, -99) and hepatic retinol (BDE-47). Despite an antioxidant-rich diet, PBDE exposure induced hepatic oxidative stress, particularly in females, with an increased hepatic GSSG:GSH ratio, a marginal increase in lipid peroxidation, and increased oxidized glutathione. Positive associations were found between concentrations of BDE-183 and thiols and, in males, between BDE-99 and reduced GSH, but a negative association occurred between BDE-99 and TBARS. Subsequently, concentrations of PBDE congeners in wild birds may alter thyroid hormone and vitamin A concentrations, glutathione metabolism and oxidative stress.
authors.affiliation: Canadian Wildlife Service, Burlington, Ontario. kim.fernie@ec.gc.ca
authors.forename: Kim J
authors.initials: KJ
authors.lastname: Fernie
authors.forename: J Laird
authors.initials: JL
authors.lastname: Shutt
authors.forename: Greg
authors.initials: G
authors.lastname: Mayne
authors.forename: David
authors.initials: D
authors.lastname: Hoffman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.forename: Ken G
authors.initials: KG
authors.lastname: Drouillard
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Ritchie
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D004781:Environmental Exposure; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity*; D046093:Falconiformes / Q000378:metabolism; D005260:Female; D005411:Flame Retardants / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism*; D055768:Halogenated Diphenyl Ethers; D006706:Homeostasis / Q000187:drug effects; D008297:Male; D010063:Ovum / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D010647:Phenyl Ethers / Q000633:toxicity*; D011075:Polybrominated Biphenyls / Q000633:toxicity*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013963:Thyroid Hormones / Q000378:metabolism; D014801:Vitamin A / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; D013963:Thyroid Hormones; D014801:Vitamin A; C086401:pentabromodiphenyl ether; D005978:Glutathione