Naeije R, Vanhaelst L, Golstein J
Horm Metab Res. 1978 Nov;10(6):521-5. doi: 10.1055/s-0028-1093383.
To investigate the most early events occurring during the adaptation of the pituitary-thyroid axis to iodine depletion, two rat populations were submitted to 4 week low iodine regimens of different severity. The variations of the following parameters were studied: pituitary thyrotropin (TSH) concentration, serum thyroxine (T4), triiodothyronine (T3) and TSH, thyroid weight and thyroid iodine concentration. In the first population, mildly iodine depleted, serum and pituitary TSH remained unchanged. The weight of the thyroid increased by the 12th day. Serum T4 dropped by the 26th day. Serum T3 tended to increase during the whole observation period. In the second population, more severely iodine depleted, the increase in thyroid weight appeared by the 4th day. Serum T3 increased from day 13 to day 20, then returned to normal. Serum TSH increased and serum T4 decreased by the 20th day. These results suggest that, in the adaptation to iodine deficiency in the rat, autonomous thyroid regulatory mechanisms play a major role at the onset of goiter growth. On the other hand, most likely a combined effect of serum T3 and T4 triggers variations in pituitary TSH secretion.
为研究垂体 - 甲状腺轴在适应碘缺乏过程中最早发生的事件，将两组大鼠分别进行为期4周的不同严重程度的低碘喂养。研究了以下参数的变化：垂体促甲状腺激素（TSH）浓度、血清甲状腺素（T4）、三碘甲状腺原氨酸（T3）和TSH、甲状腺重量及甲状腺碘浓度。在第一组轻度碘缺乏的大鼠中，血清和垂体TSH保持不变。甲状腺重量在第12天增加。血清T4在第26天下降。血清T3在整个观察期内有升高趋势。在第二组严重碘缺乏的大鼠中，甲状腺重量在第4天开始增加。血清T3在第13天至第20天升高，然后恢复正常。血清TSH在第20天升高，血清T4下降。这些结果表明，在大鼠适应碘缺乏的过程中，甲状腺自主调节机制在甲状腺肿生长开始时起主要作用。另一方面，血清T3和T4的联合作用很可能触发垂体TSH分泌的变化。
