Hu Fang, Sharma Bibek, Mukhi Sandeep, Patiño Reynaldo, Carr James A
Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409-3131, USA.
Toxicol Sci. 2006 Oct;93(2):268-77. doi: 10.1093/toxsci/kfl053. Epub 2006 Jun 28.
The purpose of this study was to determine if changes in colloidal thyroxine (T(4)) immunoreactivity can be used as a biomarker of perchlorate exposure in amphibian thyroid tissue. Larval African clawed frogs (Xenopus laevis) were exposed to 0, 1, 8, 93, and 1131 microg perchlorate/l for 38 and 69 days to cover the normal period of larval development and metamorphosis. The results of this study confirmed the presence of an immunoreactive colloidal T(4) ring in thyroid follicles of X. laevis and demonstrated that the intensity of this ring is reduced in a concentration-dependent manner by perchlorate exposure. The smallest effective concentration of perchlorate capable of significantly reducing colloidal T(4) ring intensity was 8 microg perchlorate/l. The intensity of the immunoreactive colloidal T(4) ring is a more sensitive biomarker of perchlorate exposure than changes in hind limb length, forelimb emergence, tail resorption, thyrocyte hypertrophy, or colloid depletion. We conclude that the colloidal T(4) ring can be used as a sensitive biomarker of perchlorate-induced thyroid disruption in amphibians.
本研究的目的是确定胶体甲状腺素（T4）免疫反应性的变化是否可作为两栖动物甲状腺组织中高氯酸盐暴露的生物标志物。将非洲爪蟾幼体暴露于0、1、8、93和1131微克高氯酸盐/升的环境中38天和69天，以涵盖幼体发育和变态的正常时期。本研究结果证实了非洲爪蟾甲状腺滤泡中存在免疫反应性胶体T4环，并表明该环的强度因高氯酸盐暴露而以浓度依赖性方式降低。能够显著降低胶体T4环强度的高氯酸盐最小有效浓度为8微克高氯酸盐/升。免疫反应性胶体T4环的强度是比后肢长度、前肢出现、尾部吸收、甲状腺细胞肥大或胶体耗竭变化更敏感的高氯酸盐暴露生物标志物。我们得出结论，胶体T4环可作为两栖动物中高氯酸盐诱导的甲状腺破坏的敏感生物标志物。
