hypothalamic–pituitary–prolactin axis

{{Short description|Hormone pathway}}

File:PRL structure.png, a major hormone of the HPP 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.{{cite book|author=J. Larry Jameson|title=Harrison's Endocrinology, 3E|url=https://books.google.com/books?id=yFzFQMCMOGYC|date=22 March 2013|publisher=McGraw Hill Professional|isbn=978-0-07-181487-4|page=16}}{{cite book|last1=Puetz|first1=Petra|title=Handbook of Behavioral Medicine|last2=Bellingrath|first2=Silja|last3=Gierens|first3=Andrea|last4=Hellhammer|first4=Dirk H.|year=2010|pages=659–670|doi=10.1007/978-0-387-09488-5_43|chapter=Neuroendocrine Measures in Behavioral Medicine|isbn=978-0-387-09487-8}} It is involved in lobuloalveolar maturation of the mammary glands during pregnancy and the induction and maintenance of lactation following parturition.{{cite journal | vauthors = Crowley WR | title = Neuroendocrine regulation of lactation and milk production | journal = Compr Physiol | volume = 5 | issue = 1 | pages = 255–91 | year = 2015 | pmid = 25589271 | doi = 10.1002/cphy.c140029 | isbn = 9780470650714 }} 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 peptide (VIP).{{cite book|author1=Tony M. Plant|author2=Anthony J. Zeleznik|title=Knobil and Neill's Physiology of Reproduction|url=https://books.google.com/books?id=I1ACBAAAQBAJ&pg=PA479|date=15 November 2014|publisher=Academic Press|isbn=978-0-12-397769-4|pages=479–}}