Two forms of rat placental lactogen revealed by radioimmunoassay.
Two forms of rat placental lactogen revealed by radioimmunoassay.
复制标题
放射免疫测定揭示了两种形式的大鼠胎盘催乳素。
作者：
M. Robertson;H. Friesen
用放射免疫分析法（RIA）测定了孕晚期大鼠胎盘中乳原激素（rPL）的种类。部分纯化的rPL在大鼠肝脏受体实验（RRA）中与oPRL校准为标准。当浓度为1000 ng/ml时，其他物种的PL、PRL和GH在RIA中均无交叉反应。大鼠血清PL水平在-70℃保存时保持稳定，而在-20℃保存时则不稳定。在以往使用RRA的研究中，在大鼠血清中发现了两个rPL峰，一个在第11-13天，一个在第20天。然而，通过RIA，妊娠晚期血清中只有20,000道尔顿的rPL存在免疫反应。RIA未检测到在轻度妊娠血清中主要存在的较大的40-50,000道尔顿的rPL分子种类，从而揭示了两种可能不相关的rPL形式的存在。妊娠第21天血清rPL浓度随着胎数的增加呈指数增长，最多可达9个胎。
A radioimmunoassay (RIA) has been developed to the species of lactogenic hormone (rPL) present in late pregnant rat placenta. Partially purified rPL calibrated against oPRL in the rat liver receptor assay (RRA) was used as standard. None of the PL's, PRL's, and GH's from other species cross-reacted in the RIA when tested at 1000 ng/ml. Rat serum PL levels remained stable in samples stored at -70C but not at -20C. In previous studies, using RRA, two peaks of rPL were found in rat serum, one at Day 11-13 and one at Day 20. By RIA, however, only the 20,000 dalton species of rPL present in late pregnant serum was immunoreactive. The RIA did not detect the larger, 40-50,000 dalton molecular species of rPL predominant in mild-pregnant serum, thus revealing the presence of two possibly unrelated forms of rPL. Serum rPL concentrations at Day 21 of pregnancy increased exponentially as the number of fetuses increased until a maximum of nine fetus.