Role of ovarian steroids in development of uterine binding sites for prolactin in the ferret.
Role of ovarian steroids in development of uterine binding sites for prolactin in the ferret.
复制标题
卵巢类固醇在雪貂催乳素子宫结合位点发育中的作用。
DOI：
10.1095/biolreprod48.6.1266
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发表时间：
1993
影响因子：
3.6
通讯作者：
Mead,RA
中科院分区：
文献类型：
--
作者：
Rose,J;Huang,JL;Mead,RA
本研究的目的是研究1）雪貂子宫中特异性催乳素（PRL）结合位点的存在，2）125 I标记的绵羊PRL（oPRL）结合位点的子宫定位，3）假妊娠过程中子宫PRL结合位点的变化，4）卵巢激素对PRL结合位点的调节。通过使用125 I-oPRL和来自50，000 × g颗粒部分的300-800 μg蛋白质测定结合。最佳结合发生在25°C下6小时内。饱和度数据的Scatchard分析揭示了一组高亲和力（Kd= 4.99 × 10−11± 0.88 M），低容量（22.76 ± 1.62 fmol/mg）的结合位点。激素特异性分析显示，绵羊生长激素（oGH）与oPRL的子宫结合位点发生交叉反应，取代了38%的结合配体。然而，在牛促甲状腺激素（bTSH）、绵羊LH（oLH）或绵羊FSH（oFSH）过量500倍的情况下，125 I-oPRL结合没有受到抑制，这表明位于腔上皮和腺上皮中的结合位点具有激素特异性。结合到雪貂子宫膜的催乳素在假妊娠的前半部分增加，在第21天和第28天之间达到平台，然后下降。在假孕第1天，雪貂子宫中PRL结合位点的浓度为4.91 ± 0.42 fmol/mg蛋白。卵巢切除增加了PRL结合（7.51 ± 0.12 fmol/mg），而卵巢切除和雌二醇（4.42 ± 0.12 fmol/mg）或孕酮（4.57 ± 0.03 fmnol/mg）治疗使PRL结合位点的浓度降低到与假孕第1天无显著差异的水平。去卵巢雪貂经雌二醇和孕酮处理后，PRL结合位点的浓度最高（8.09 ± 0.02fmol/mg）。这些数据表明，卵巢类固醇在子宫PRL结合位点的发展中发挥作用，但这些类固醇相互作用，以增强PRL结合的机制尚不清楚。
The objectives of this study were to investigate 1) the presence of specific prolactin (PRL) binding sites in the ferret uterus, 2) the uterine location of125I-labeled ovine PRL (oPRL) binding sites, 3) changes in uterine PRL binding sites during pseudo-pregnancy, and 4) regulation of PRL binding sites by ovarian steroids. Binding was determined through use of125I-oPRL and 300–800 μg of protein from the 50,000 ×gparticulate fraction. Optimal binding occurred within 6 h at 25°C. Scatchard analysis of saturation data revealed a single set of high-affinity (Kd= 4.99 × 10−11± 0.88 M), low-capacity (22.76 ± 1.62 fmol/mg) binding sites. Analysis of hormonal specificity revealed that ovine growth hormone (oGH) cross-reacted with oPRL for the uterine binding sites, displacing 38% of the bound ligand. However, no inhibition of125I-oPRL binding occurred in the presence of a 500-fold excess of bovine thyroid-stimulating hormone (bTSH), ovine LH (oLH), or ovine FSH (oFSH), suggesting hormonal specificity of the binding sites that are located in the luminal and glandular epithelium. Prolactin binding to ferret uterine membranes increased during the first half of pseudopregnancy, plateaued between Days 21 and 28, and then declined. The concentration of PRL binding sites in uteri of ferrets on Day 1 of pseudopregnancy was 4.91 ± 0.42 fmol/mg of protein. Ovariectomy increased PRL binding (7.51 0.12 fmol/mg), whereas ovariectomy and treatment with either estradiol (4.42 _ 0.12 fmol/mg) or progesterone (4.57 ± 0.03 fmnol/mg) reduced the concentration of PRL binding sites to levels not significantly different from that on Day 1 of pseudopregnancy. Ovariectomized ferrets treated with estradiol and progesterone exhibited the highest concentration of PRL binding sites (8.09 ± 0.02 fmol/mg). These data suggest that ovarian steroids have a role in the development of uterine PRL binding sites, but the mechanism by which these steroids interact to enhance PRL binding is unknown.