title: Thyroid disrupting effects of polychlorinated biphenyls in ovariectomized rats: A benchmark dose analysis.
abstract: Polychlorinated biphenyls (PCBs) are proved endocrine disrupting potentials. Reference points (RP) for PCBs are derived from dose-response relationship analysis by using the traditional no observed adverse effect or lowest observed adverse effect level (NOAEL/LOAEL) methods, or a more advanced benchmark dose (BMD) method. In present study, toxicological RP for PCBs' thyroid disruption was established and compared between NOAEL/LOAEL and BMD method in an ovariectomized (OVX) rat model. Sham and OVX controls were given corn oil while other OVX groups were administered with 0.1, 1.0, 5.0, and 10.0mg/kg bw of PCBs (aroclor 1254) respectively by gavage. Body weight change, liver type I 5'-deiodinase (5'-DI) activity, serum total thyroxine (tT4), triiodothyroxine (tT3), thyroid stimulating hormones (TSH), and thyroid histopathological changes were measured and analyzed. In PCBs-treated groups, serum tT4, tT3, TSH, and histopathological examinations showed significant changes with a dose-dependent manner compared with those in OVX control (P<0.05). The toxicological RP for PCBs affecting thyroid function of OVX rats was 0.02 mg/kg'bw based on BMD analysis.
authors.affiliation: Key laboratory of food safety risk assessment, Ministry of Health (China National Center for Food Safety Risk Assessment), 100022, Beijing, China; Chinese Center for Disease Control and Prevention, 100021, Beijing, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key laboratory of food safety risk assessment, Ministry of Health (China National Center for Food Safety Risk Assessment), 100022, Beijing, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key laboratory of food safety risk assessment, Ministry of Health (China National Center for Food Safety Risk Assessment), 100022, Beijing, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Jia
authors.affiliation: Sichuan University, Sichuan, 610041, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: Southwest University, Chongqing, 400716, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Su
authors.affiliation: Key laboratory of food safety risk assessment, Ministry of Health (China National Center for Food Safety Risk Assessment), 100022, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key laboratory of food safety risk assessment, Ministry of Health (China National Center for Food Safety Risk Assessment), 100022, Beijing, China. Electronic address: liuzhaoping@cfsa.net.cn.
authors.forename: Zhaoping
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D019055:No-Observed-Adverse-Effect Level; D010052:Ovariectomy; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013963:Thyroid Hormones / Q000097:blood*; D013974:Thyroxine / Q000097:blood
chemical_list: D013963:Thyroid Hormones; D011078:Polychlorinated Biphenyls; D013974:Thyroxine
keywords: Benchmark dose analysis; Polychlorinated biphenyls; Reference points; Thyroid disruption