title: The impact of prolonged cadmium exposure and co-exposure with polychlorinated biphenyls on thyroid function in rats.
abstract: Endocrine-disrupting chemicals currently represent one of the major concerns and this study was aimed to investigate the effects of different doses of cadmium, widespread toxic metal, on the levels of thyroid hormones and to calculate Benchmark doses for these effects. Furthermore, the effects of co-exposure to cadmium and polychlorinated biphenyls on thyroid function were investigated. Six orally-treated groups of rats were receiving 0.3, 0.6, 1.25, 2.5, 5 and 10mgCd/kgb.w./day, five groups were orally treated with 0.5, 1, 2, 4 and 8mgPCBs/kgb.w./day, while nine groups of rats were orally-treated with different dose combinations of Cd and PCBs (0.6, 1.25 and 2.5mgCd/kgb.w. and 2, 4 and 8mgPCBs/kgb.w./day), during 28 days. Thyroid hormones were adversely affected by cadmium, with most prominent effect observed on triiodothyroxine levels indicating Cd interference with thyroid function at extrathyroidal level. Calculated Benchmark doses for Cd effects on thyroid hormones indicate triiodothyroxine as the most sensitive one that can be used as a basis for risk assessment. This study also implicates possible synergistic effects of Cd and PCBs on thyroid function as a consequence of their interference at different levels of thyroid homeostasis.
authors.affiliation: Department of Toxicology "Akademik Danilo Soldatović", University of Belgrade, Faculty of Pharmacy, Vojvode Stepe 450, Belgrade, Serbia. Electronic address: aleksandra@pharmacy.bg.ac.rs.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Buha
authors.affiliation: Department of Toxicology "Akademik Danilo Soldatović", University of Belgrade, Faculty of Pharmacy, Vojvode Stepe 450, Belgrade, Serbia.
authors.forename: Biljana
authors.initials: B
authors.lastname: Antonijević
authors.affiliation: Department of Toxicology "Akademik Danilo Soldatović", University of Belgrade, Faculty of Pharmacy, Vojvode Stepe 450, Belgrade, Serbia.
authors.forename: Zorica
authors.initials: Z
authors.lastname: Bulat
authors.affiliation: Poison Control Center, Military Medical Academy, Crnotravska 17, Belgrade, Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Jaćević
authors.affiliation: Chemicals Department, Ministry of Energy, Development and Environmental Protection of Republic of Serbia, Ruze Jovanovic 27a, Belgrade, Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Milovanović
authors.affiliation: Department of Toxicology "Akademik Danilo Soldatović", University of Belgrade, Faculty of Pharmacy, Vojvode Stepe 450, Belgrade, Serbia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Matović
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D008297:Male; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D051381:Rats; D013961:Thyroid Gland / Q000187:drug effects* / Q000473:pathology; D013963:Thyroid Hormones / Q000097:blood; D015430:Weight Gain / Q000187:drug effects
chemical_list: D013963:Thyroid Hormones; D002104:Cadmium; D011078:Polychlorinated Biphenyls
keywords: 5′-monodeiodinases; 5′D-I; ANOVA; BMD; BMR; CED; CEDL(05); CES; Cadmium; Cd; Co-exposure; ECLIA; EDCs; FT3; FT4; Fisher's least significant difference; LSD; PCBs; Polychlorinated biphenyls; RTW; Rats; T3; T4; TEF; TSH; Thyroid-disrupting chemicals; benchmark dose; benchmark response; cadmium; critical effect dose; critical effect size; electrochemiluminescent immunoassay; endocrine-disrupting chemicals; free thyroxine; free triiodothyroxine; lower confidence levels; one-way analysis; polychlorinated biphenyls; relative thyroid gland weight; thyroid stimulating hormone; thyroxine; toxicity equivalent factor; triiodothyroxine