Boado R, Ulloa E, Zaninovich A A
Acta Endocrinol (Copenh). 1983 Mar;102(3):386-91. doi: 10.1530/acta.0.1020386.
In the present work the effects of oestradiol benzoate (EB) on pituitary and plasma concentrations of TSH, plasma T4 and T3, and thyroidal activity of male and female rats have been studied. Wistar rats weighing between 150 to 200 g were injected sc with varying doses of EB in corn oil for 9 or 30 days. The animals were exsanguinated by cardiac puncture and the hypophyses removed and individually homogenized at 4 degrees C in 200 microliters PBS buffer. Pituitary and plasma TSH were measured by radioimmunoassay. Thyroidal activity was evaluated by a 4 h 131I uptake and by 48 h thyroidal release plasma slopes derived form the ratio PB[125I] (from thyroidal secretion) to PB[131I] (from exogenous [131I]T4). In both male and female rats the 10 and 25 micrograms doses of EB produced a significant decrease in pituitary TSH content; this effect was more pronounced when the 25 micrograms dose was given over 30 days. Plasma T4 decreased significantly; plasma T3 was moderately elevated in all groups (NS) and significantly increased in female rats treated with 25 micrograms EB (P less than 0.01). It is concluded that EB induced a marked depression of intrapituitary TSH, probably due to a decrease in synthesis, without affecting the release of TSH into the circulation. Moreover, EB accelerated peripheral T4 kinetics and thyroid gland activity, albeit to a moderate degree.
在本研究中，已对苯甲酸雌二醇（EB）对雄性和雌性大鼠垂体及血浆中促甲状腺激素（TSH）浓度、血浆甲状腺素（T4）和三碘甲状腺原氨酸（T3）水平以及甲状腺活性的影响进行了研究。体重在150至200克之间的Wistar大鼠皮下注射不同剂量的溶于玉米油的EB，持续9天或30天。通过心脏穿刺对动物进行放血，并取出垂体，于4℃在200微升磷酸盐缓冲液（PBS）中单独匀浆。采用放射免疫分析法测定垂体和血浆中的TSH。通过4小时131I摄取量以及由甲状腺分泌的PB[125I]与外源性[131I]T4的PB[131I]之比得出的48小时甲状腺释放血浆斜率来评估甲状腺活性。在雄性和雌性大鼠中，10微克和25微克剂量的EB均使垂体TSH含量显著降低；当给予25微克剂量并持续30天时，这种效应更为明显。血浆T4显著降低；所有组中血浆T3均有中度升高（无统计学意义），而在接受25微克EB治疗的雌性大鼠中显著升高（P<0.01）。结论是，EB导致垂体TSH显著降低，可能是由于合成减少，而不影响TSH释放进入循环。此外，EB加速了外周T4的动力学过程和甲状腺活性，尽管程度适中。
