全氟辛磺酸对于爪蟾的甲状腺激素干扰效应

Thyroid disrupting effects of perfluorooctane sulfonate on Xenopus laevis

运用两栖类变态实验（AMA）研究了全氟辛磺酸（PFOS）对于非洲爪蟾（Xenopuslaevis）蝌蚪的生长、变态和甲状腺组织结构的影响．结果显示，与对照组相比，7d后，10，50和250μμg·L^-1。PFOS暴露组蝌蚪的后肢长分别减小了17％，11％和18％，蝌蚪的发育延缓了1～2个阶段；19d后，10，50和250μg·L^-1PFOS组蝌蚪的体重分别增加了17％，10％和20％，体长分别增加了5％，4％和6％，而10μg·L^-1和250μg·L^-1。PFOS组蝌蚪的后肢长分别减小了12％和13％；暴露组甲状腺组织结构出现滤泡数目减少、上皮细胞增生、胶质减少甚至滤泡溶通等现象．结论是，在本实验浓度下，PFOS对于非洲爪蟾的蝌蚪生长有促进作用，对于变态发育过程却有抑制作用．参照AMA的方法，可以判断PFOS为抗甲状腺激素干扰物．

The amphibian metamorphosis assay （AMA） was used to detect thyroid disrupting effects of perfluorooctane sulfonate （PFOS）. Xenopus laevis tadpoles at stage 51 were exposed to 10, 50 and 250 μg·L^-1 PFOS. The growth, metamorphosis and thyroid histology were observed. After 7 days of exposure, the hind limb l, engths were decreased by 11%- 18 %, and 1 or 2 developmental stages were delayed in treatment groups compared with the control. After 19 days of exposure, the body weights were increased by 10%-20%, the body lengths were increased by 4%-6%, and the hind limb lengths were decreased by 12%-13% in treatment groups. PFOS decreased the number of thyroid follicles, in which cell hyperplasia, colloid deple- tion and vaeuolation were observed. These results suggested that PFOS inhibited the develop- ment and increased the growth of X laevis. According to AMA, our results indicated that PFOS was an anti-thyroid hormone disrupting chemical.