Zhu B R, Li B
School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan 430065, China.
Hubei Center for Disease Control and Prevention, China.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi. 2019 Sep 26;32(1):78-82. doi: 10.16250/j.32.1374.2019085.
To examine the effect of niclosamide on thyroid endocrine disruption in larval zebrafish.
Zebrafish embryos (2 hours post-fertilization) were exposed to niclosamide at concentrations of 0, 5, 10, 20, 40 μg/L and 80 μg/L until 120 hours post-fertilization, and the body weight, hatching rate, malformation rate and survival rate of zebrafish embryos/larvae were measured. In addition, the triiodothyronine (T3) and thyroxin (T4) activities were determined in zebrafish, and the expression of and genes that were associated with the regulation of thyroid hormones was quantified using a quantitative real-time PCR (qPCR) assay.
Following exposure to niclosamide, there was no concentration-dependent hatching rate ( = 0.947, = 0.924) or body weight of larval zebrafish ( = 1.042, = 0.409); however, there were concentration-dependent survival rate ( = 9.309, = 0.005) and malformation rate ( = 14.900, = 0.001). As compared to controls, exposure to niclosamide at concentrations of 40 μg/L and 80 μg/L resulted in a significant reduction in the survival rate (both values < 0.05), and a marked rise in the malformation rate of larval zebrafish (both values < 0.05). In addition, the T4 activity increased ( = 0.927, = 6.858, = 0.003) and T3 activity decreased ( = 0.925, = 8.212, = 0.001) in larval zebrafish with the concentration of niclosamide. qPCR assay determined up-regulation of gene expression ( = 0.840, = 9.032, = 0.002) and down-regulation of gene expression ( = 0.952, = 9.130, = 0.002).
Niclosamide exposure at environmental related concentrations may cause thyroid endocrine disruption of larval zebrafish.
研究氯硝柳胺对斑马鱼幼体甲状腺内分泌干扰的影响。
将受精后2小时的斑马鱼胚胎暴露于浓度为0、5、10、20、40μg/L和80μg/L的氯硝柳胺中，直至受精后120小时，测量斑马鱼胚胎/幼体的体重、孵化率、畸形率和存活率。此外，测定斑马鱼体内三碘甲状腺原氨酸（T3）和甲状腺素（T4）的活性，并使用定量实时PCR（qPCR）测定法对与甲状腺激素调节相关的 和 基因的表达进行定量分析。
暴露于氯硝柳胺后，斑马鱼幼体的孵化率（ = 0.947， = 0.924）或体重（ = 1.042， = 0.409）不存在浓度依赖性；然而，存活率（ = 9.309， = 0.005）和畸形率（ = 14.900， = 0.001）存在浓度依赖性。与对照组相比，暴露于浓度为40μg/L和80μg/L的氯硝柳胺导致斑马鱼幼体的存活率显著降低（两个 值均<0.05），畸形率显著升高（两个 值均<0.05）。此外，随着氯硝柳胺浓度的增加，斑马鱼幼体的T4活性升高（ = 0.927， = 6.858， = 0.003），T3活性降低（ = 0.925， = 8.212， = 0.001）。qPCR测定法确定 基因表达上调（ = 0.840， = 9.032， = 0.002）， 基因表达下调（ = 0.952， = 9.130， = 0.002）。
在与环境相关的浓度下暴露于氯硝柳胺可能会导致斑马鱼幼体甲状腺内分泌干扰。
