Prolactin is a hormone necessary for lactation. Prolactin is produced in the anterior pituitary gland. Under normal conditions, prolactin is chronically inhibited by dopamine from the hypothalamus. Increased levels of dopamine will further inhibit prolactin release and can lower levels. This can be a problem after giving birth, when lactation is necessary for breast feeding.

On the Other: Increased levels can persist in certain conditions

Certain drugs, such as dopamine antagonists, can block dopamine's effect on the anterior pituitary gland. This will influence prolactin levels independent of normal dopamine levels. Prolactin levels are continually elevated with patients with prolactinomas, which are pituitary adenomas. Prolactin levels are normally above 150 micrograms per liter and will respond to dopamine agonists that inhibit further prolactin production and release.

Bottom Line

Dopamine administration does lower prolactin levels. The production and release of prolactin from the anterior pituitary gland in the head is controlled by constant dopamine inhibition. Factors that increase or decrease dopamine will in turn effect prolactin levels.

Source:

Young, V. Blueprints: Medicine. Lippincott Williams & Wilkins: Baltimore, 2007.