[Studies on the intercompartmental relationship of PRL secretion during human pregnancy--maternal, fetal, and...

Although it is well established that PRL is present in the maternal serum, fetal serum, and amniotic fluid during human pregnancy, the precise interrelationship among those three compartments is unknown. In order to elucidate the intercompartmental relationship, several experiments were undertaken. Results are as follows: 2. The concentration of amniotic fluid PRL was different from that of maternal or fetal serum PRL during gestation. 2. There was no correlation between amniotic fluid and maternal or cord serum PRL at delivery. 3. Although bromocriptine suppressed the secretion of maternal serum PRL abruptly, the concentration of amniotic fluid PRL remained unchanged after the administration of bromocriptine at mid-gestation. 4. Analysis of molecular size of PRL by Sephadex G-100 column gel filtration revealed that the elution profiles of maternal serum PRL, fetal serum PRL, and amniotic fluid PRL differed from one another and furthermore, they were similar to those of adult pituitary PRL, fetal pituitary PRL, and decidual PRL, respectively. 5. PRL which was secreted from decidua could transfer to amniotic cavity across the fetal membrane. 6. Decidual PRL and amniotic fluid PRL have a biological activity. These results suggest that three compartments of PRL secretion during human pregnancy are independent each other and, furthermore, possible origin of amniotic fluid PRL is decidua.