Cidlowski J A, Muldoon T G
Endocrinology. 1975 Jul;97(1):59-67. doi: 10.1210/endo-97-1-59.
The influence of induced variations in circulating levels of thyroid hormones upon the estrogen receptor content of rat uterine, anterior pituitary and hypothalamic cytosol fractions has been investigated. Sucrose gradient centrifugation analyses showed no observable effects of thyroidectomy or acute induced hyperthyroidism upon receptor levels in uterus hypothalamus of ovariectomized rats, but an apparent positive thyroidal influence upon anterior pituitary receptor content. Qualitatively, the receptor complex sedimentation coefficients were unaltered. Binding assays showed that thyroid hormone administration to the ovariectomized rat resulted in a marked increase in pituitary receptor content, whereas the same treatment had no significant effect on the pituitary receptor level of the intact animal. Conversely, a marked fall in uterine receptor content was found in thyroxine-treated intact, but not castrate, animals. The changes in measurable receptor levels could not be attributed to competition for estrogen binding sites by thyroxine or triiodothyronine. Pituitary receptor content of ovariectomized rats was studied following administration of varying levels of thyroxine; 5 mug/day significantly depressed receptor levels, while enhancement of binding capacity was occasioned by levels of thyroxine ewual to or greather than 25 mug/day. The hypothalamus was completely unaffected by similar treatment and the uterus responded with decreased receptor level only at the highest dosage used. Thyroxine replacement reversed the decrease in anterior pituitary receptor concentration detectable following thyroidectomy. The effect of the thyroid hormones on the pituitary receptor content was not a result of changes in the capability of the tissue to respond to estrogen-induced synthesis of receptor.
研究了甲状腺激素循环水平的诱导变化对大鼠子宫、垂体前叶和下丘脑胞质溶胶部分雌激素受体含量的影响。蔗糖梯度离心分析表明，甲状腺切除术或急性诱导的甲状腺功能亢进对去卵巢大鼠子宫和下丘脑的受体水平没有明显影响，但对垂体前叶受体含量有明显的甲状腺正向影响。定性地说，受体复合物的沉降系数没有改变。结合试验表明，给去卵巢大鼠注射甲状腺激素会导致垂体受体含量显著增加，而相同处理对完整动物的垂体受体水平没有显著影响。相反，在甲状腺素处理的完整动物而非去势动物中，发现子宫受体含量显著下降。可测量受体水平的变化不能归因于甲状腺素或三碘甲状腺原氨酸对雌激素结合位点的竞争。研究了给去卵巢大鼠注射不同水平甲状腺素后垂体受体含量的变化；每天5微克显著降低受体水平，而每天25微克或更高水平的甲状腺素则导致结合能力增强。下丘脑不受类似处理的影响，子宫仅在使用的最高剂量下受体水平降低。甲状腺素替代可逆转甲状腺切除术后垂体前叶受体浓度的下降。甲状腺激素对垂体受体含量的影响不是组织对雌激素诱导的受体合成反应能力变化的结果。
