Thyroid hormones (TH) are important for development, growth, and metabolism. It is also clear that the synthesis and secretion of TH are regulated by the hypothalamic-pituitary-thyroid (HPT) axis. Animal models have helped advance our understanding of the roles and regulatory mechanisms of TH. The animals' bodies develop through coordinated timing of cell division and differentiation. Studies of frog metamorphosis led to the discovery of TH and their role in development. However, to adapt to rhythmic environmental changes, animals also developed various endocrine rhythms. Studies of rodents clarified the neural and molecular mechanisms underlying the circadian regulation of the HPT axis. Moreover, birds have a sophisticated seasonal adaptation mechanism, and recent studies of quail revealed unexpected roles for thyroid-stimulating hormone (TSH) and TH in the seasonal regulation of reproduction. Interestingly, this mechanism is conserved in mammals. Thus, we review how animal studies have shaped our general understanding of the HPT axis in relation to biological rhythms.

中文翻译：

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下丘脑-垂体-甲状腺轴和生物学节律：使用动物模型发现了TSH的意外作用。

甲状腺激素（TH）对发育，生长和代谢很重要。同样清楚的是，TH的合成和分泌受下丘脑-垂体-甲状腺（HPT）轴的调节。动物模型有助于增进我们对TH的作用和调节机制的了解。动物的身体通过协调的细胞分裂和分化时间而发育。青蛙变态的研究导致TH的发现及其在发育中的作用。然而，为了适应有节奏的环境变化，动物也发展出各种内分泌节律。啮齿动物的研究阐明了HPT轴的昼夜节律调节的神经和分子机制。此外，鸟类具有完善的季节性适应机制，最近的鹌鹑研究表明，甲状腺刺激激素（TSH）和TH在繁殖的季节性调节中具有意想不到的作用。有趣的是，这种机制在哺乳动物中是保守的。因此，我们回顾了动物研究如何塑造了我们对与生物节律有关的HPT轴的一般理解。