Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. EPA, Research Triangle Park, NC, United States.
Environ Toxicol Pharmacol. 2007 Sep;24(2):194-7. doi: 10.1016/j.etap.2007.04.008. Epub 2007 Apr 27.
Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a chlorinated phenolic antibacterial compound found as an active ingredient in many personal care and household products. The structural similarity of triclosan to thyroid hormones and recent studies demonstrating activation of the human pregnane X receptor (PXR) and inhibition of diiodothyronine (T(2)) sulfotransferases, have raised concerns about adverse effects on thyroid homeostasis. The current research tested the hypothesis that triclosan alters circulating concentrations of thyroxine. The hypothesis was tested using a 4-day oral triclosan exposure (0-1000mg/kg/day) in weanling female Long-Evans rats, followed by measurement of circulating levels of serum total thyroxine (T(4)). Dose-dependent decreases in total T(4) were observed. The benchmark dose (BMD) and lower bound on the BMD (BMDL) for the effects on T(4) were 69.7 and 35.6mg/kg/day, respectively. These data demonstrate that triclosan disrupts thyroid hormone homeostasis in rats.
三氯生（5-氯-2-（2,4-二氯苯氧基）苯酚）是一种氯化酚类抗菌化合物，作为许多个人护理和家用产品的有效成分被发现。三氯生与甲状腺激素的结构相似，以及最近的研究表明其能激活人体孕烷 X 受体（PXR）并抑制二碘甲状腺原氨酸（T(2)) 磺基转移酶，这引起了对甲状腺稳态产生不良影响的担忧。目前的研究检验了三氯生改变循环甲状腺素浓度的假设。该假设通过对断奶雌性 Long-Evans 大鼠进行为期 4 天的口服三氯生暴露（0-1000mg/kg/天）来测试，然后测量血清总甲状腺素（T(4)) 的循环水平。观察到总 T(4) 呈剂量依赖性降低。T(4) 效应的基准剂量（BMD）和 BMD 的下限（BMDL）分别为 69.7 和 35.6mg/kg/天。这些数据表明三氯生破坏了大鼠的甲状腺激素稳态。
