Hypothalamic-like releasing hormones of the placenta.

The challenge to define the hypothalamic-like hormones and to determine where they are produced in the placenta and how they control the production of other hormones such as human chorionic gonadotropin, progesterone, and estrogen, is an important current topic of investigation. This article reviews the existing data that have indicated or established the existence of placental hypothalamic-like peptide hormones.