Placental Lactogen/CSH1: Proteins and Enzymes

Human Placental Lactogen (abbreviated PL or hPL), also called chorionic somatomammotropin hormone 1 (abbreviated CSH1), is a member of the prolactin/growth hormone (PRL/GH) family. PL is mainly expressed by cells in the syncytiotrophoblast layer of the placenta, which produce increasing amounts of PL as pregnancy proceeds. The major portion enters the maternal circulation, while a smaller amount circulates in the fetus. Reduced stimulation of PL by angiotensin 2 correlates with intrauterine growth restriction.