Léan A D, Ferland L, Drouin J, Kelly P A, Labrie F
Endocrinology. 1977 Jun;100(6):1496-504. doi: 10.1210/endo-100-6-1496.
The effect of estradiol and thyroid hormone treatment on pituitary TRH binding and TSH and PRL responses to the neurohormone was studied. A significant increase in the number of pituitary TRH binding sites was observed between 2 and 4 days after daily administration of estradiol benzoate with a plateau at 300% of control being reached at 7 days. Plasma PRL levels showed a similar early pattern of response. In animals rendered hypothyroid by a 2-month treatment with propylthiouracil or 1 month after surgical thyroidectomy, the level of pituitary TRH receptors was increased approximately 2-fold, this elevation being completely reversed by treatment with thyroid hormone. Estradiol-17beta administered with L-thyroxine partially reversed the inhibitory effect of thyroid hormone on TRH receptor levels in hypothyroid animals. The antagonism between estrogens and thyroid hormone is also apparent on the TSH response to TRH since estrogen administration can reverse the marked inhibition by thyroxine of the TSH response to TRH either partially or completely in intact and hypothyroid animals, respectively. The PRL response to TRH is 55 and 40% inhibited in hypothyroid and intact rats, respectively, by thyroid hormone when combined with estrogen treatment. The present data clearly show that estrogens and thyroid hormones can affect TSH and PRL secretion, the effect of estrogens being predominantly on PRL secretion while thyroid hormone affects mainly TSH. The close correlation observed between the level of TRH receptors and PRL and TSH responses to TRH suggests that estrogens and, to a lesser extent, thyroid hormones, exert their action by modulation of the level of receptors for the neurohormone in both thyrotrophs and mammotrophs.
研究了雌二醇和甲状腺激素治疗对垂体促甲状腺激素释放激素（TRH）结合以及促甲状腺激素（TSH）和催乳素（PRL）对该神经激素反应的影响。每日给予苯甲酸雌二醇后2至4天，观察到垂体TRH结合位点数量显著增加，7天时达到对照的300%并趋于平稳。血浆PRL水平呈现类似的早期反应模式。在用丙硫氧嘧啶治疗2个月或甲状腺切除术后1个月导致甲状腺功能减退的动物中，垂体TRH受体水平增加约2倍，甲状腺激素治疗可完全逆转这种升高。与L-甲状腺素一起给予的17β-雌二醇可部分逆转甲状腺激素对甲状腺功能减退动物TRH受体水平的抑制作用。雌激素与甲状腺激素之间的拮抗作用在TSH对TRH的反应中也很明显，因为分别在完整和甲状腺功能减退的动物中，给予雌激素可部分或完全逆转甲状腺素对TSH对TRH反应的显著抑制。当与雌激素治疗联合时，甲状腺激素分别使甲状腺功能减退和完整大鼠中PRL对TRH的反应受到55%和40%的抑制。目前的数据清楚地表明，雌激素和甲状腺激素可影响TSH和PRL的分泌，雌激素的作用主要在PRL分泌上，而甲状腺激素主要影响TSH。在TRH受体水平与PRL和TSH对TRH的反应之间观察到的密切相关性表明，雌激素以及在较小程度上甲状腺激素，通过调节促甲状腺细胞和催乳细胞中神经激素受体的水平发挥其作用。
