(PRL) The hormones produced by the pituitary gland to stimulate the production of milk in the breasts. Produced in increasing amount during pregnancy, although milk secretion is postponed until levels of estrogen and progesterone fall after the baby is born. For more on prolactin in the animal kingdom, and its importance in being produced by decidual cells in pregnancy.

An increase in serum prolactin; can be accompanied by galactorrhea and amenorrhea.

Measurement of prolactin in serum. An increase is called hyperprolactinemia.

The glandular part of the pituitary gland, lying toward the front, so in medical speak called the anterior pituitary. Produces follicle stimulating hormone, luteinising hormone and prolactin. Other hormones include hormones that: (1) cause normal childhood growth (growth hormone), (2) drive the thyroid gland (thyroid stimulating hormone, or TSH), and (3) drive the adrenal gland (adrenocorticotropic hormone, or ACTH). See also hypothalamus and neurohypophysis.

A drug that mimics dopamine, which is produced by the hypothalamus to normally inhibit production of prolactin by the pituitary gland. Specific treatment for hyperprolactinemia: the tablets are given by mouth unless they cause side effects, in which case the same tablets (but not the capsules) can be used vaginally! Made by Sandoz as Parlodel.

imilar to bromocriptine, but more potent and with fewer side effects; used once or twice weekly to lower production of prolactin in hyperprolactinemia. Not yet approved for infertility treatment, but no adverse fetal effects have been reported when used for ovulation induction.

Plump endometrial stromal cells, lying between the glands of the endometrium, formed under the prolonged influence of progesterone, especially with establishment of pregnancy. Constitutes the decidual reaction to form the decidua of pregnancy, and produce prolactin (important for regulating water entering the gestational sac) and relaxin, which keeps the myometrium quiet.

Demonstrable milk production from the breasts other than while purposefully breast-feeding; caused by hyperprolactinemia or, sometimes, by disease in the breast or wall of the chest.

A tumor, usually benign, of the pituitary gland, usually resulting in amenorrhea and anovulation. Often there is an increase (sometimes substantial) in serum prolactin. If the tumor is itself secreting prolactin it is called a prolactinoma. But other tumors can occur, some of which secrete other pituitary hormones. The tumor grows inside a confined space with walls of bone called the pituitary fossa: if it is still small and confined to the fossa we call the tumor a microadenoma; if it enlarges the fossa or pushes out of it, it is a macroadenoma, and is both more dangerous and capable of producing visual symptoms and headaches. Diagnosed on a CAT scan or a MRI scan. Prolactin-secreting microadenomas can usually be treated just with drugs.