农药二巯基敌枯双对FRTL-5细胞合成甲状腺球蛋白的影响

The Disruptive Effect of N'N-methylene-bis on the Function of FRTL-5 Cells

目的观察农药二巯基敌枯双对FRTL-5细胞株合成甲状腺球蛋白的影响,并探讨其作用机制以及FRTL-5细胞株用于筛选环境甲状腺素干扰物的可能性。方法FRTL-5细胞分别经0.1、1.0和10.0μg/mL二巯基敌枯双染毒处理48 h后,用酶组织化学法测定培养液中甲状腺球蛋白的浓度;用活细胞爬片的酶细胞化学染色观察细胞内甲状腺过氧化物酶的表达强度,并用透射电镜观察最高浓度处理组细胞的超微结构。结果随二巯基敌枯双浓度的增大,FRTL-5细胞培养液中甲状腺球蛋白的浓度逐渐降低,其中0.1、1.0μg/mL浓度组与溶剂对照组相比差异有统计学意义(P<0.05),10.0μg/mL浓度组培养液中未能检出甲状腺球蛋白;酶细胞化学染色未见染毒组细胞甲状腺过氧化物酶活性改变,图像分析结果显示其阳性细胞的积分光密度(IOD)值与对照组相比,差异无统计学意义(P>0.05);细胞超微结构观察发现染毒组细胞出现粗面内质网扩张。结论二巯基敌枯双可能是通过损伤甲状腺滤泡细胞的粗面内质网,从而影响甲状腺球蛋白的合成与分泌;FRTL-5细胞培养液中甲状腺球蛋白的浓度可以作为体外筛选环境甲状腺素干扰物的敏感指标之一。

Objective To study the impact of N＇ N-methylene-bis on thyroglobulin produced by FRTL-5 cells, and to explore the potential of using FRTL-5 cells to screen environmental thyroid hormone disruptors in vitro. Methods The FRTL-5 cells were treated with 0.1, 1.0 and 10. 0 μg/mL N＇N-methylene-bis for 48 hours, respectively. The concentrations of thyroglobulin in the medium of the treated cells were detected by radioimmunoassay. The expression of thyroid peroxidases in the FRTL-5 cells was assessed by enzyme cytochemistry technique. The ultrastructure of the cells was also observed. Results The FRTL-5 cells treated with 0.1 and 1. 0 μg/mL of N＇ N-methylene-bis produced less thyroglobulin than the controls （P〈 0. 05）. No thyroglobulin was detected with the cells treated with 10. 0 μg/mL of N＇ N-methylene-his. No difference in the expression of thyroid peroxidases was found between the treated cells and the controls. The treated cells had expanded rough endoplasmic retieulum. Conclusion N＇ N-methylene-bis disrupts the bio-function of thyroid by damaging the rough endoplasmic reticulum of thyroid follicular cells. FRTL-5 cells can be used for screening thyroid hormone disruptors in vitro.