[Effects and toxicity mechanism of 2,2',4,4'-tetrabrominated diphenyl ethers on the homeostasis of thyroid hormone system in C57BL/6 mice].
OBJECTIVE
To investigate the effects and of toxicity mechanism of 2,2',4,4'-TETRABDE (BDE-47) on TT3, TT4 and TSH in C57BL/6 mice.


METHODS
C57BL/6 mice were divided randomly into 4 groups, and given with corn oil (control group) and 1 micromol/(kg x d), 10 micromol/(kg x day) and 100 micromol/(kg x day) BDE-47 for 4 days through intraperitoneal injection respectively. After collecting the bloods, livers and thyroids, the T3, T4 and TSH levels of serum were detected by electro chemiluminescenc (ECLI), thyroid peroxidase (TPO) activities in thyroid by guaiacol method and type-I deiodinase (DI) in liver by CHOPRA method.


RESULTS
Compared with the control group, the level of TT4 decreased significantly in the three BDE-47 dose groups, TT3 in the medium and high dose groups decreased significantly, and the activities of DI increased in the medium and high dose groups significantly (P < 0.05), whereas TSH level in serum and activity of TPO in thyroid in the three dose groups weren't statistically significant comparing with control group.


CONCLUSIONS
BDE-47 could affect the homeostasis of thyroid hormone system, and activity of type-I deiodinase (DI) in liver being changed might be the one of toxicity mechanisms.
Liu
Zaoling
Z
School of Public Health of Xinjiang Medicial University, Urumchi 830054, China. yiliuzhimei@sohu.com
Liu
Jiwen
J
Zhang
Jianqing
J
Tian
Yanan
Y
Fang
Daokui
D
Huang
Haiyan
H
Jiang
Yousheng
Y
Zhou
Jian
J
Zhang
Hongyu
H
Mei
Shujiang
S
D000818:Animals; D005260:Female; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity*; D006706:Homeostasis / Q000187:drug effects*; D007453:Iodide Peroxidase / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D055768:Halogenated Diphenyl Ethers; D013963:Thyroid Hormones; D014284:Triiodothyronine; C511295:2,2',4,4'-tetrabromodiphenyl ether; D013972:Thyrotropin; D007453:Iodide Peroxidase; D013974:Thyroxine