Markoff E, Talamantes F
Endocrinology. 1982 Feb;110(2):403-8. doi: 10.1210/endo-110-2-403.
Serum, placental, extracts, and placental incubation medium from 12- and 17-day-pregnant mice were fractionated by gel exclusion chromatography on Sephadex G-100. The eluates were monitored for activity by a radioreceptor assay (RRA) for lactogenic hormones that detects placental lactogen (PL) and PRL. RRA activity in serum and placental extracts and incubation medium from both days of gestation eluted in two peaks, the first emerging in the void volume (Vo) and the second with an elution volume (Ve) to Vo ratio of 1.96, which was similar to the Ve to Vo ratio of a human PL marker. Fractions in the second peak stimulated casein synthesis in mouse mammary gland explants. The RRA activity of the eluates was not due to the presence of PRL, as determined by RIA, and therefore the activity in the second peak was identified as monomeric PL. Electrophoresis of mouse placental extracts and incubation medium from both days 12 and 17 of gestation on 10% polyacrylamide gels showed only one band of RRA activity (Rf = 0.22). The present results show there are no differences between the elution profiles on Sephadex G-100 and the electrophoretic mobilities of PL from serum, placental extracts, and placental incubation media from days 12 and 17 of pregnancy in mice.
对妊娠12天和17天小鼠的血清、胎盘提取物以及胎盘培养液进行葡聚糖凝胶G - 100凝胶排阻色谱分离。通过检测胎盘催乳素（PL）和催乳素（PRL）的催乳激素放射受体分析（RRA）监测洗脱液的活性。妊娠这两天的血清、胎盘提取物和培养液中的RRA活性以两个峰洗脱，第一个峰出现在空体积（Vo）处，第二个峰的洗脱体积（Ve）与Vo的比值为1.96，这与人PL标志物的Ve与Vo比值相似。第二个峰中的组分刺激了小鼠乳腺外植体中的酪蛋白合成。通过放射免疫分析（RIA）确定，洗脱液的RRA活性不是由PRL的存在引起的，因此第二个峰中的活性被鉴定为单体PL。妊娠第12天和17天的小鼠胎盘提取物和培养液在10%聚丙烯酰胺凝胶上进行电泳，仅显示一条RRA活性带（迁移率Rf = 0.22）。目前的结果表明，小鼠妊娠第12天和17天的血清、胎盘提取物以及胎盘培养液中PL在葡聚糖凝胶G - 100上的洗脱图谱和电泳迁移率之间没有差异。
