Leow Melvin Khee-Shing
Department of Endocrinology, Division of Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.
J Theor Biol. 2007 Sep 21;248(2):275-87. doi: 10.1016/j.jtbi.2007.05.016. Epub 2007 May 18.
The mathematical model proposed focuses on the description of the behavior of the interaction between thyrotropin (i.e. thyroid-stimulating hormone (TSH)) and thyroid hormones with the objective of providing a better understanding of the behavior of TSH-T4 relationship in health and in disease. The normal pituitary-thyroid axis is tightly coupled and regulated with a servomechanism. In the physiological situation, any elevation of thyroid hormones will inhibit TSH secretion by the thyrotrophs of the pituitary, which in turn lead to an appropriate reduction in stimulation of the thyroid, accompanied by a decline of thyroid hormones towards normal. Similarly, a decline in thyroid hormones represents a potent input signal that when sensed by the pituitary thyrotrophs, will result in an increase of TSH output by the latter to accelerate the synthesis and secretion of thyroid hormones to drive the state towards normal equilibrium. Using this model, the profound sensitivity of thyrotrophs to feedback by thyroid hormones can be appreciated and understood better in the context of diseases of thyroid hormone excess and deficiency.
所提出的数学模型着重描述促甲状腺激素（即甲状腺刺激激素（TSH））与甲状腺激素之间的相互作用行为，目的是更好地理解健康和疾病状态下TSH - T4关系的行为。正常的垂体 - 甲状腺轴通过一种伺服机制紧密耦合和调节。在生理情况下，甲状腺激素的任何升高都会抑制垂体促甲状腺细胞分泌TSH，这反过来又会导致对甲状腺刺激的适当减少，同时甲状腺激素水平下降至正常。同样，甲状腺激素水平下降是一个有力的输入信号，当垂体促甲状腺细胞感知到该信号时，会导致后者TSH输出增加，以加速甲状腺激素的合成和分泌，使状态恢复到正常平衡。利用这个模型，可以在甲状腺激素过多和缺乏疾病的背景下，更好地理解和认识促甲状腺细胞对甲状腺激素反馈的高度敏感性。
