State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, Zhejiang, PR China.
Crop Germplasm Resources Institute, Jilin Academy of Agricultural Sciences, Changchun, 136100, PR China.
Ecotoxicology. 2020 Jul;29(5):584-593. doi: 10.1007/s10646-020-02206-3. Epub 2020 May 28.
Bifenthrin (BF) and acetochlor (AT) are widely used as an insecticide and herbicide, respectively, which are introduced to the aquatic environment as a natural result. Although the thyroid active substances may coexist in the environment, their joint effects on fish have not been identified. We examined the joint toxicity of BF and AT in zebrafish (Danio rerio) in this study. An acute lethal toxicity test indicated that the median lethal concentration (LC) values of BF and AT under 96 h treatment were 0.40 and 4.56 µmol L, respectively. The binary mixture of BF + AT displayed an antagonistic effect on the acute lethal toxicity. After 14 days post fertilization (dpf) with exposure to individual pesticides at sub-lethal concentrations of, no effects were observed on the catalase (CAT) and peroxidase (POD) activities, while the binary mixtures (except for the 7.2 × 10 µmol L BF + 1.2 × 10 µmol L AT exposure group) significantly induced the CAT activity. The superoxide dismutase (SOD) activity and triiodothyronine (T3) level were significantly increased in all exposure groups. The thyroxine (T4) level remained unchanged after exposure to individual pesticides, but significantly increased in the 7.2 × 10 µmol L BF + 1.2 × 10 µmol L AT group. The expressions of the genes Dio2, TRa, TSHβ and CRH in the thyroid hormone (TH) axis were significantly up-regulated in the 7.2 × 10 µmol L BF + 0.4 × 10 µmol L AT group. Our data indicated that the binary mixture of BF + AT significantly altered the antioxidant enzyme activities and gene expressions in the hypothalamic-pituitary-thyroid (HPT) axis and changed the TH levels.
联苯菊酯（BF）和乙草胺（AT）分别作为杀虫剂和除草剂被广泛使用，它们作为一种自然产物被引入到水生环境中。尽管甲状腺活性物质可能同时存在于环境中，但它们对鱼类的联合作用尚未得到确定。在本研究中，我们检查了 BF 和 AT 对斑马鱼（Danio rerio）的联合毒性。急性致死毒性试验表明，BF 和 AT 在 96 h 处理下的半数致死浓度（LC）值分别为 0.40 和 4.56 μmol·L-1。BF+AT 的二元混合物对急性致死毒性表现出拮抗作用。在亚致死浓度暴露 14 天后，单独使用农药对过氧化氢酶（CAT）和过氧化物酶（POD）活性没有影响，而二元混合物（除了 7.2×10μmol·L BF+1.2×10μmol·L AT 暴露组外）显著诱导 CAT 活性。超氧化物歧化酶（SOD）活性和三碘甲状腺原氨酸（T3）水平在所有暴露组中均显著升高。单独使用农药后甲状腺素（T4）水平保持不变，但在 7.2×10μmol·L BF+1.2×10μmol·L AT 组中显著增加。甲状腺激素（TH）轴中 Dio2、TRa、TSHβ 和 CRH 基因的表达在 7.2×10μmol·L BF+0.4×10μmol·L AT 组中显著上调。我们的数据表明，BF+AT 的二元混合物显著改变了下丘脑-垂体-甲状腺（HPT）轴中的抗氧化酶活性和基因表达，并改变了 TH 水平。
