多氯联苯（Aroclor 1254）对非洲爪蟾变态发育的影响

为了研究多氯联苯(Aroclor 1254)对非洲爪蟾变态发育的影响,将非洲爪蟾受精卵暴露在一定浓度(0、400ng·L-1、2μg·L-1、10μg·L-1、20μg·L-1)的Aroclor 1254中,直至完全变态.结果表明,20μg·L-1Aroclor1254暴露可使变态所需时间显著延长(p<0.05),低于20μg·L-1的各组变态所需时间与对照组无显著差异.2μg·L-1以上的Aroclor1254暴露可使蝌蚪甲状腺发生明显的组织学改变,包括甲状腺组织滤泡扩张、胶体面积相对缩小,滤泡细胞增殖、高度增加,并且这种变化随暴露剂量的增加而愈发明显.提示多氯联苯可干扰非洲爪蟾的变态发育,引起甲状腺组织学改变.采用定量组织病理学技术检测甲状腺激素干扰物较为灵敏,方法简单易行,是一种切实可行的筛选和确证甲状腺干扰物的体内方法.

Effects of Polychlorinated Biphenyls (Aroclor 1254) on Metamorphic Development of Xenopus Laevis

In this study, Xenopus laevis were exposed to Aroclor 1254 at doses(0, 400ng·L-1, 2μg·L-1, 10μg·L-1, 20μg·L-1)from oosperm to completed metamorphosis. The effects of Aroclor 1254 on metamorphic development of X. laevis were observed. The time to finish metamorphosis of X. laevis exposed at the highest dose(20μg·L-1)was extended. Thyroid histology of X. laevis changed in exposed groups over 2μg·L-1, including follicle expansion, colloid area decrease, epithelium hyperplasia and epithelium height increase. The response became obvious with increasing dose. These results indicated that polychlorinated biphenyls can disrupt the metamorphosis of X. laevis, and induce histological change of thyroid gland. The assay of quantitative histopathology is a simple and sensitive method to screen thyroid hormone disruptors.