Studies of prolactin secretion in human pregnancy

Abstract

Recent studies have confirmed the presence of a separate human prolactin (HPr) molecule. Measurement of HPr concentrations has been performed in normal and abnormal gestation and during the menstrual cycle. HPr rises throughout gestation with a return to prepregnant concentrations by the seventh postpartum day. Variable increases in plasma prolactin were observed after intravenous administration of arginine, especially after the thirtieth week of gestation. Puerperally, prolactin rises in response to suckling. Amniotic fluid prolactin levels are one hundred times those of maternal or fetal blood. No significant change in basal HPr is seen during the menstrual cycle. The ability to measure this new pituitary polypeptide by radioimmunoassay permits investigation of its role in human gestation. © 1972.