title: Alteration of thyroid hormone concentrations in juvenile Chinook salmon (Oncorhynchus tshawytscha) exposed to polybrominated diphenyl ethers, BDE-47 and BDE-99.
abstract: Polybrominated diphenyl ethers (PBDEs) have been used as flame-retardants in consumer products and are currently detected in salmon globally. The two most predominant PBDE congeners found in salmon are BDE-47 (2,2',4,4'-tetrabromodiphenyl ether) and BDE-99 (2,2',4,4',5-pentabromodiphenyl ether). In the present study, groups of juvenile Pacific Chinook salmon were fed five environmentally relevant concentrations of either BDE-47 (0.3-552 ng total PBDEs/g food), BDE-99 (0.3-580 ng total PBDEs/g food), or nearly equal mixtures of both congeners (0.7-690 ng total PBDEs/g food) for 39-40 days. The concentrations of circulating total thyroid hormones, thyroxine (T4) and 3,5,3'-triiodothyronine (T3), were measured using a hormone-specific time-resolved fluoroimmunoassay to determine if PBDE exposure disrupts the hypothalamic-pituitary-thyroid endocrine axis. The concentrations of both circulating T4and T3were altered in juvenile salmon by dietary uptake of BDE-99. Exposure to BDE-47 did not alter either T3or T4circulating hormone concentrations. However, exposure to a mixture of BDE-47 and BDE-99 reduced T3in fish with lower concentrations of total whole body PBDEs than with either congener alone at equivalent PBDE whole body concentrations. Accordingly, the disruption of PBDEs on circulating thyroid hormone concentrations has the potential to impact a number of critical functions in juvenile salmon including growth, parr-smolt transformation, and immunological processes.
authors.affiliation: Environmental & Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA. Electronic address: mary.arkoosh@noaa.gov.
authors.forename: Mary R
authors.initials: MR
authors.lastname: Arkoosh
authors.affiliation: Frank Orth & Associates, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA.
authors.forename: Ahna L
authors.initials: AL
authors.lastname: Van Gaest
authors.affiliation: Frank Orth & Associates, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA.
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Strickland
authors.affiliation: Frank Orth & Associates, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA.
authors.forename: Greg P
authors.initials: GP
authors.lastname: Hutchinson
authors.affiliation: Frank Orth & Associates, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA.
authors.forename: Alex B
authors.initials: AB
authors.lastname: Krupkin
authors.affiliation: Environmental & Fisheries Science Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2032 South East OSU Drive, Newport, OR 97365, USA.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Dietrich
mesh_terms: D000818:Animals; D004032:Diet; D055768:Halogenated Diphenyl Ethers / Q000494:pharmacology*; D012474:Salmon / Q000097:blood* / Q000254:growth & development; D013963:Thyroid Hormones / Q000097:blood*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
chemical_list: C477694:2,2',4,4',5-brominated diphenyl ether; D055768:Halogenated Diphenyl Ethers; D013963:Thyroid Hormones; D014284:Triiodothyronine; C511295:2,2',4,4'-tetrabromodiphenyl ether; D013974:Thyroxine
keywords: Chinook salmon; Endocrine disruption; PBDE; T3, T4; Thyroid hormones