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 apoplexy The pituitary gland consists of two parts, the anterior (front) and posterior (back) pituitary. Both parts release hormones that control numerous other organs. In pituitary apoplexy, the main initial problem is a lack of secretion of adrenocorticotropic hormone (ACTH, corticotropin), which stimulates the secretion of cortisol by the adrenal gland. This occurs in 70% of those with pituitary apoplexy. A sudden lack of cortisol in the body leads to a constellation of symptoms called "adrenal crisis" or "Addisonian crisis" (after a complication of Addison's disease, the main cause of adrenal dysfunction and low cortisol levels). The main problems are low