<unk> , a major hormone of the HPP axis. The<unk>  (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<unk>  (PRL; luteotropin) from the lactotrophs of the pituitary gland into the circulation and the subsequent action of<unk>  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<unk>  from the pituitary gland include dopamine <unk> -inhibiting factor", or "PIF"), estradiol, progesterone, thyrotropin-releasing hormone (TRH), and vasoactive intestinal peptide (VIP).
Hypothalamic–pituitary–prolactin axis
Hypothalamic–pituitary–somatotropic axis
Hypothalamic–pituitary–gonadal axis
Hypothalamic–pituitary–thyroid axis
Hypothalamic–pituitary–adrenal axis
Sympathoadrenal system
Ovarian reserve
Adipose-derived hormones