Two binding sites for estradiol in rat uterine nuclei: relationship to uterotropic response.
Two binding sites for estradiol in rat uterine nuclei: relationship to uterotropic response.
复制标题
大鼠子宫核中雌二醇的两个结合位点：与促子宫反应的关系。
作者：
B. Markaverich;J. H. Clark
雌激素可导致去卵巢大鼠子宫核中两种特异结合成分的增加。其中一个位点(I型)代表雌激素受体，它以高亲和力(解离常数，1 NM)和低容量(1pmol/子宫)与雌二醇结合，并从细胞质转移到细胞核。第二组分(第二类)与雌二醇的结合能力高于第一类结合部位，并呈现S型饱和曲线。因此，不能准确地估计离解常数。雌二醇和雌三醇对II型部位的不同刺激表明，这是一种特异的雌激素反应，与子宫生长高度相关。单次注射雌二醇会导致I型子宫部位的长期滞留(>；6小时)，II型子宫部位的快速和持续抬高(1-72小时)，以及真正的子宫生长。与之相反，注射雌三醇可引起I型部位的快速增加，但并不伴有I型部位的增多。
Estradiol administration causes an increase in two specific binding components in uterine nuclei of mature ovariectomized rats. One of these sites (type I) represents the estrogen receptor which binds estradiol with high affinity (dissociation constant, 1 nM) and low capacity (1 pmol/uterus) and is translocated from the cytoplasm to the nucleus. The second component (type II) binds estradiol with a higher capacity than type I sites and displays a saturation curve which is sigmoidal. Hence, no accurate estimation of the dissociation constant can be made. The differential stimulation of type II sites by estradiol and estriol suggests that this is a specific estrogenic response and is highly correlated with uterine growth. A single injection of estradiol results in long term retention of type I sites (>6 h), rapid and sustained elevations of type II sites (1-72 h), and true uterine growth. In contrast, estriol injection caused a rapid increase in type I sites which was not accompanied by an increase in typ e...