Endocrine functions of the human placenta: lessons from the life line

The placenta, which is an association of maternal and fetal tissues which develops during pregnancy in most mammals, has been developed during the transition from oviparity to viviparity in order to facilitate the intrauterine development of the fetus. It functions as an extremely efficient endocrine gland; an equivalent of the hypothalamo-pituitary-gonadal axis, though transient in nature. This is well exemplified by the human placenta which elaborates protein, peptide and steroid hormones which regulate the development of the fetus and also maintain the pregnancy. Results obtained in our studies reveal that the synthesis and secretion of the protein and steroid hormones by the human placenta is subject to regulatory mechanisms that are similar, though not identical, to those operative in the hypothalamo-pituitary-gonadal axis