Hyperprolactinemia is a pituitary disorder that can present with .
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Which of the following is the most likely mechanism of the therapeutic effect of Bromocriptine in female patients with hyperprolactinemia to help increase fertility?
Content Reviewers:Rishi Desai, MD, MPH
With hyperprolactinemia, hyper- means above, -prolactin refers to the hormone produced by the pituitary gland, and -emia refers to the blood, so hyperprolactinemia means higher than normal prolactin levels in the blood.
Normally, at the base of the brain, there’s a small pea-sized gland called the pituitary gland.
The anterior pituitary - the front of the pituitary gland - has a number of different cells, each of which secretes a different hormone.
Apart from milk production, high levels of prolactin also inhibit the release of gonadotropin releasing hormone from the hypothalamus, which results in decreased luteinizing and follicle stimulating hormone levels, which in turn, decreases estrogen levels.
In women, this can stop ovulation and menstruation, which is why women typically don’t have a menstrual period while breastfeeding. In women that are not pregnant or breastfeeding, and in men, prolactin levels are usually kept in check by the hypothalamus in two ways.
The first way is the most important, and it’s when the hypothalamus secretes a constant stream of dopamine which is also called prolactin inhibiting factor.
Dopamine binds to specific receptors on the lactotrophs and inhibits the release of prolactin. The second way is when the hypothalamus secretes thyrotropin releasing hormone, also called prolactin releasing hormone, which can stimulate prolactin release.
If the level of prolactin rises for any reason, then it signals the hypothalamus to release more dopamine, eventually decreasing its own production, a process called negative feedback or feedback inhibition.
Hyperprolactinemia can develop a few different ways. The first is physiologic hyperprolactinemia, which is what happens during pregnancy and lactation - and levels of prolactin typically return back to normal afterwards.
Another cause is a prolactinoma, a type of pituitary adenoma, a benign tumor of lactotroph cells which grow uncontrollably and make excess amounts of prolactin. There are also systemic causes of hyperprolactinemia like hypothyroidism.