PITUITARY PEPTIDES IN PRIMATE FETUSES

Abstract

This chapter discusses the pituitary peptides in primate fetuses. The human fetal hypothalamus–pituitary gland appears to contain all the biologically active peptides that are characteristic of the adult from the earliest stage at which it is possible to obtain material for study. The chapter presents current evidence on the pituitary peptides—namely, the adrenocorticotropic/lipotropic hormone group and the neurohypophyseal hormones (oxytocin and vasopressin). With both of these groups of hormones, there is a common functional theme—the initiation of parturition. The fetal pituitary gland is considered to play a primary role in the endocrine control of labor, more especially, to act as the trigger that alters the balance between other fetoplacental hormones in such a way as to stimulate myometrial contractility. There are two hypothalamic–pituitary systems that may be concerned, to varying degrees, in this process. The fetal pituitary is essential to the growth and development of the fetal adrenal gland. In humans, anencephaly is associated with adrenal atrophy and has a major effect on the timing of delivery.