Iversen E, Laurberg P
Second University Clinic of Internal Medicine, Kommunehospitalet, Aarhus C, Denmark.
Endocrinology. 1988 Feb;122(2):385-8. doi: 10.1210/endo-122-2-385.
Small amounts of TRH are present in the thyroid, and TRH has been shown in several studies to have a moderate direct inhibitory effect on TSH-stimulated thyroid hormone secretion. In a recent publication, however, data were presented to demonstrate that very low doses of TRH given in short pulses induce immediate increases in T4 secretion from the thyroid. This type of secretion had never been observed previously. We have tried to reproduce these results employing perfused dog thyroid lobes in which small and rapid variations in the release of hormones from the follicular cells are easily detected. TRH was infused in concentrations ranging from 1.7 X 10(-11) to 1.7 X 10(-8) M for 10-min periods. There was no effect on thyroid secretion of T4 and T3, nor did the infusion of 1.7 X 10(-9) M TRH for 160 min alter the T4 secretion induced by 4 microU/ml TSH.
甲状腺中存在少量促甲状腺激素释放激素（TRH），多项研究表明，TRH对促甲状腺激素（TSH）刺激的甲状腺激素分泌具有中等程度的直接抑制作用。然而，最近有一篇论文指出，短脉冲给予极低剂量的TRH可使甲状腺立即增加甲状腺素（T4）的分泌。此前从未观察到这种分泌类型。我们试图利用灌注犬甲状腺叶来重现这些结果，在这种情况下，很容易检测到滤泡细胞激素释放的微小快速变化。以1.7×10⁻¹¹至1.7×10⁻⁸M的浓度输注TRH，持续10分钟。这对T4和三碘甲状腺原氨酸（T3）的甲状腺分泌没有影响，以1.7×10⁻⁹M的TRH输注160分钟也未改变4微单位/毫升TSH诱导的T4分泌。
