Nakao J, Chang W C, Murota S I, Orimo H
Atherosclerosis. 1981 Jan-Feb;38(1-2):75-80. doi: 10.1016/0021-9150(81)90105-2.
To determine whether aortic smooth muscle cells possess estradiol receptors or not, an estradiol binding study has been performed in cultured rat aortic smooth muscle cells by using an intact-cell assay. Specific binding for estradiol is shown by the cells, and the binding reaches a plateau after 15 min of incubation at 37 degrees C. The binding curve shows a saturable binding process. Scatchard analysis reveals a single population for estradiol binding with a dissociation constant of 5.0 X 10(-8) M and specific binding sites of 64 fmole per 10(6) cells (38,500 sites per cell). Molecular specificity shows highly specific binding with estradiol. Among various steroids tested, only testosterone at 10(-5) M competes slightly (9.3%) with the estradiol-specific binding. These data indicate the existence of specific, high-affinity and limited-capacity binding sites for estradiol in rat aortic smooth muscle cells. This accords with the concept that estrogen responsiveness in aortic smooth muscle cells is mediated through the estrogen-receptor binding in the cells.
为了确定主动脉平滑肌细胞是否具有雌二醇受体，通过完整细胞检测法对培养的大鼠主动脉平滑肌细胞进行了雌二醇结合研究。细胞显示出对雌二醇的特异性结合，并且在37℃孵育15分钟后结合达到平台期。结合曲线显示出可饱和的结合过程。Scatchard分析揭示了雌二醇结合的单一群体，解离常数为5.0×10⁻⁸ M，每10⁶个细胞的特异性结合位点为64飞摩尔（每个细胞38,500个位点）。分子特异性显示与雌二醇具有高度特异性结合。在测试的各种类固醇中，仅10⁻⁵ M的睾酮与雌二醇特异性结合有轻微竞争（9.3%）。这些数据表明大鼠主动脉平滑肌细胞中存在雌二醇的特异性、高亲和力和有限容量的结合位点。这与主动脉平滑肌细胞中的雌激素反应性通过细胞中的雌激素受体结合介导的概念一致。
