Kelly P A, Shiu R P, Robertson M C, Friesen H G
Endocrinology. 1975 May;96(5):1187-95. doi: 10.1210/endo-96-5-1187.
A placental lactogen or chorionic mammotropin (rCM) has been identified in the serum of pregnant rats by radioreceptor assay (RRA). Two peaks of activity were found, the first between days 11-13 and the second between days 17-21 of pregnancy. Gel filtration of day 12 serum or placental extracts revealed two peaks of lactogenic activity, the first eluting ahead of and the second appearing immediately after 125I-hPRL (human prolactin). On the other hand, when serum or placental extracts from day 17-21 pregnant rats were fractionated in the same manner, only a single peak of lactogenic activity was eluted after 125I-hPROL. The placental concentration of rCM increased from 11 mug/g wet weight at day 12 to 74 mug/g at days 14-15, after which the concentration declined to 29 mug/g on day 21. Electrophoresis of a fraction from G-100 column of a day 12 0r day 20 placental extract or serum with a V-e/V-o ratio of 2.08 revealed a single peak of lactogenic activity by RRA with an Rf equal to 0.43. Large MW rCM (V-e/V-o ratio of 1.35) from serum had an Rf equal to 0.52 whereas the large MW species from placental extracts had a mobility similar to that of small MW fraction. The half-time disappearance rate of serum rCM on day 12 is 19.5 min compared to 1.2 min on days 17-21 of pregnancy.
通过放射受体分析法（RRA）在怀孕大鼠血清中鉴定出一种胎盘催乳素或绒毛膜促乳腺素（rCM）。发现了两个活性峰，第一个在怀孕第11 - 13天之间，第二个在怀孕第17 - 21天之间。对第12天血清或胎盘提取物进行凝胶过滤，显示出两个催乳活性峰，第一个峰在125I - hPRL（人催乳素）之前洗脱，第二个峰在125I - hPRL之后立即出现。另一方面，当以相同方式对怀孕第17 - 21天大鼠的血清或胎盘提取物进行分级分离时，只有一个催乳活性峰在125I - hPROL之后洗脱。rCM的胎盘浓度从第12天的11微克/克湿重增加到第14 - 15天的74微克/克，之后在第21天浓度降至29微克/克。对第12天或第20天胎盘提取物或血清的G - 100柱级分进行电泳，V - e/V - o比值为2.08，通过RRA显示出一个单一的催乳活性峰，Rf等于0.43。血清中大分子质量rCM（V - e/V - o比值为1.35）的Rf等于0.52，而胎盘提取物中的大分子质量物质的迁移率与小分子质量级分相似。怀孕第12天血清rCM的半衰期消失率为19.5分钟，而在怀孕第17 - 21天为1.2分钟。
