甲状腺素干扰物对甲状腺滤泡细胞分泌甲状腺球蛋白功能的影响

Effects of Thyroid Hormone Disruptors on Secretion of Thyroglobulin in the Fischer Rat Thyroid Cell Line FRTL-5

目的了解几种典型甲状腺素干扰物对甲状腺滤泡(FRTL-5)细胞分泌甲状腺球蛋白功能的影响,探讨其干扰甲状腺素水平的细胞学机制及建立甲状腺素干扰物甄别方法的可行性。方法将大鼠FRTL-5细胞体外培养后接种于24孔培养板,每孔细胞数2×105个,待细胞贴壁后分别加入受试物丙硫氧嘧啶、叶枯宁[N,N-甲撑-双(2-氨基-5-巯基-1,3,4-噻二唑)]、磺胺二甲嘧啶和杀草强,各设1组溶剂对照,置CO2孵箱培养48h后,每孔取1ml培养液,用放射免疫法测定甲状腺球蛋白的浓度。结果4个实验组的甲状腺球蛋白浓度与对照组相比均降低,差异有显著性(P<0.05),且可能存在剂量-效应关系。结论降低甲状腺细胞合成或分泌甲状腺球蛋白可能是这4种甲状腺素干扰物的作用机制之一。FRTL-5细胞分泌甲状腺球蛋白的功能是一个相对灵敏的指标,与其他体内体外实验结合可用于甲状腺素干扰物的一阶段甄别(初筛)方法。

Objective To study the effects of some typical thyroid hormone disruptors on secretion of thyroglobulin(Tg)in the Fischer rat thyriod line(FRTL-5)cells and to explore the cellular mechanism of their effects on thyroxine level and the fea-sibility of FRTL-5cells being used in screening thyroid hormone disruptors.Methods The FRTL-5cells were cultured in vitro,then were inoculated in24-cavity medium,2×10 5 cell per cavity,and were exposed to various dose of propylthiouracil,N,N-methylene-bis(2-amino-5-sulfhydryl-1,3,4-thiadiazole),sulfamethazine and Amitrole.Solvent control groups were established for every dose group.After48h-incubation in CO 2 incubator,1ml hatching fluid was collected from every cavity for determination of the concentration of Tg in the medium respectively by radioimmunoassay.Results The concentration of Tg in FRTL-5cells exposed to propylthiouracil,N,N-methylene-bis(2-amino-5-sulfhydryl-1,3,4-%hiadiazole),sulfamethaine and Amitrole were sig-nificantly lower than that of the related control(P<0.05).There might be certain dose-effect relationship.Conclu sion Reduc-tion of the synthesis or secretion of Tg in thyroid cells might be one of the mechanisms of these thyroid hormone disruptors.Se-cretion of Tg in the FRTL-5cells was a relatively sensitive marker,and it might be used in discriminating thyroid hormone dis-ruptors when combining with other in vivo or in vitro experiment s as phaseⅠscreening approach.