Jayatilak P G, Glaser L A, Basuray R, Kelly P A, Gibori G
Proc Natl Acad Sci U S A. 1985 Jan;82(1):217-21. doi: 10.1073/pnas.82.1.217.
Previous studies have strongly, but indirectly, suggested that rat decidual tissue produces a prolactin-like hormone, decidual luteotropin, which markedly affects luteal cell function. However, it was also found that extracts of decidual tissue do not cross-react with antisera to either rat or ovine prolactin (PRL). The purpose of this study was to determine whether the decidual tissue contains a substance that binds to PRL receptors in rat luteal membranes and, if so, to identify, quantitate, and characterize this molecule with the use of an ovarian radioreceptor assay. Decidual tissue was induced in day 5 pseudopregnant rats by scratching the antimesometrial wall of the uterus; it was collected on day 9 and homogenized and extracted. Decidual tissue extracts bound specifically to ovarian PRL receptors. Graded dilutions of the extracts yielded curves that were parallel to the ovine PRL standard, indicating that decidual luteotropin competes for the same receptor sites on rat luteal membranes. To determine the levels of decidual luteotropin throughout pseudopregnancy, decidual tissue was obtained on each day between days 6-12. The PRL-like activity was detectable in decidual tissue as early as day 6, reached a maximum on day 9, and declined thereafter. The elution profile obtained from gel filtration of a day 9 decidual tissue extract displayed a major component of decidual luteotropin eluting at a Ve/Vo ratio of approximately equal to 2.0. Column chromatography indicated that decidual luteotropin corresponds to a protein with a molecular weight of 23,500. The hormone was heat labile, digestible by trypsin, and appears to contain disulfide linkages. In summary, this study reports the identification, quantitation, and partial characterization of a PRL-like hormone produced by the decidual tissue of the rat.
以往的研究已有力但间接表明，大鼠蜕膜组织能产生一种催乳素样激素，即蜕膜促黄体素，它能显著影响黄体细胞功能。然而，研究还发现，蜕膜组织提取物与大鼠或绵羊催乳素（PRL）的抗血清不发生交叉反应。本研究的目的是确定蜕膜组织中是否含有一种能与大鼠黄体膜上的PRL受体结合的物质，若有，则利用卵巢放射受体分析法对该分子进行鉴定、定量和特性描述。在第5天的假孕大鼠中，通过刮擦子宫的抗中膜壁诱导产生蜕膜组织；在第9天收集该组织并进行匀浆和提取。蜕膜组织提取物能特异性地与卵巢PRL受体结合。提取物的梯度稀释产生的曲线与绵羊PRL标准曲线平行，表明蜕膜促黄体素能竞争大鼠黄体膜上相同的受体位点。为了确定整个假孕期间蜕膜促黄体素的水平，在第6 - 12天的每一天都获取蜕膜组织。早在第6天就能在蜕膜组织中检测到PRL样活性，在第9天达到最高，此后下降。从第9天的蜕膜组织提取物进行凝胶过滤得到的洗脱图谱显示，蜕膜促黄体素的主要成分在Ve/Vo比值约等于2.0时洗脱。柱色谱法表明，蜕膜促黄体素对应一种分子量为23,500的蛋白质。该激素对热不稳定，可被胰蛋白酶消化，且似乎含有二硫键。总之，本研究报告了对大鼠蜕膜组织产生的一种PRL样激素的鉴定、定量和部分特性描述。
