| 摘要: |
| 甲状腺激素在鱼类的生长、发育、生殖等过程中均起着至关重要的作用，环境内分泌干扰物能够通过不同途径干扰硬骨鱼的甲状腺轴。本研究在介绍硬骨鱼下丘脑-垂体-甲状腺轴调控机制以及甲状腺激素在鱼体内动态变化过程的基础上，从甲状腺激素的合成、转运、转化、代谢以及清除等角度，总结了目前常用于指示鱼类甲状腺轴受干扰的指标，并从甲状腺轴生物标志物的研发、环境内分泌干扰物活体暴露时间和浓度选择、体外/体内相结合评价体系的建立以及微观水平指标与宏观水平指标相结合的角度，展望了该领域今后的研究重点和方向，以期为环境内分泌干扰物对鱼类甲状腺轴干扰作用研究提供更多的参考。 |
| 关键词: 环境内分泌干扰物 硬骨鱼 甲状腺轴 甲状腺激素 |
| DOI：10.11758/yykxjz.20151218001 |
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| Research Advancement in the Endocrine Disrupting Chemical Effects on Hypothalamus-Pituitary-Thyroid Axis of Teleost |
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TIAN Hua, ZHANG Xu, RU Shaoguo, ZHANG Xiaona
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College of Marine Life Sciences , Ocean University of China, Qingdao 266003
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| Abstract: |
| n teleost, thyroid hormones (THs) regulate growth, development, and reproduction, under the modulation of the hypothalamus-pituitary-thyroid (HPT) axis. Recent research has implicated that multiple endocrine disturbing chemicals (EDCs) in the environment can interfere with the HPT axis of teleost through different pathways. In fish, the corticotropin-releasing hormone (CRH) produced in the hypothalamus stimulates the synthesis and secretion of the thyroid stimulating hormone (TSH) in the pituitary, which further increases the synthesis and secretion of extrathyroidal L-thyroxine (T4) in the thyroid. T4 binds to the transthyretin (TTR) in the plasma and is transported to the peripheral tissue. 3,3¢,5-triiodo-L-thyronine (T3), the most active thyroid hormone, is formed by T4 deiodination, and acts mainly by binding to the specific nuclear thyroid hormone receptors (TRs). On the basis of introducing the regulatory mechanisms of the HPT axis and the dynamic changes of THs in teleost, this study summarized the commonly-used indexes indicating the interference effects of EDCs on the HPT axis, in the aspects related to the synthesis, transportation, transformation, metabolism, and clearance of THs. These indexes involve the histological structure of thyroid, mRNA expressions of crh gene in the hypothalamus and tshβ in the pituitary, mRNA expressions of nis, tg, tpo genes in the thyroid, TTR levels in the plasma, iodothyronine deiodinases levels and mRNA expressions of ugt1ab and sult1st5 genes in the peripheral tissues, TRs levels in the target tissue and THs levels in the plasma or the whole body homogenesis of fish. Furthermore, research emphasis and directions in this field include the development of biomarkers for the HPT axis, the selection of exposure time and dose of EDCs for in vivo tests, the establishment of evaluation systems combining both in vivo and in vitro tests, and the integration of indicators at both the microscopic and macroscopic levels, are also prospected in this study to provide more theoretical references for related investigation. |
| Key words: Endocrine disrupting chemicals Teleost Hypothalamus-pituitary-thyroid axis Thyroid hormone |
