Hypothalamic–pituitary–prolactin axis Hypothalamic–pituitary–prolactin axis The hypothalamic–pituitary–prolactin axis (HPP axis), also known as the hypothalamic–pituitary–mammary axis or hypothalamic–pituitary–breast axis, is a hypothalamic–pituitary axis which includes the secretion of prolactin (PRL; luteotropin) from the lactotrophs of the pituitary gland into the circulation and the subsequent action of prolactin on tissues such as, particularly, the mammary glands or breasts. It is involved in lobuloalveolar maturation of the mammary glands during pregnancy and the induction and maintenance of lactation following parturition. Hormones that control the secretion of prolactin from the pituitary gland include dopamine ("prolactin-inhibiting factor", or "PIF"), estradiol, progesterone, thyrotropin-releasing hormone (TRH), and vasoactive intestinal
Pituitary gland referred to the pituitary gland by only using the (Ancient Greek) name ἀδήν, "gland". He described the pituitary gland as part of a series of secretory organs for the excretion of nasal mucus. Anatomist Andreas Vesalius translated ἀδήν with "glans, in quam pituita destillat", "gland in which slime ("pituita") drips". Besides this 'descriptive' name, Vesalius used "glandula pituitaria", from which the English name "pituitary gland" is ultimately derived. The expression "glandula pituitaria" is still used as official synonym beside "hypophysis" in the official Latin nomenclature "Terminologia Anatomica". In the seventeenth century the supposed function of the pituitary gland to produce