Prolactin and Infertility

Prolactin (PRL) is one of several hormones that are produced by the pituitary gland. PRL has many different roles throughout the body, and most of those are clearly shown as clinical symptom. Perhaps the most important classical role of prolactin is to stimulate milk production in women after the delivery of a baby. Prolactin levels increase during pregnancy causing the mammary glands to enlarge in preparation for breastfeeding and ready to secrete colostrums closely after delivery. Later on the elevated prolactin levels help with the sustained production of milk during nursing. The somatomammotrop cells of the anterior pituitary gland synthesize and secrete prolactin, which is under the control of hypothalamic factors, mainly the tonic inhibition of Dopamine (DA). There are several other sources of PRL-like substances in the periphery such as placental lactogens, (similar to pituitary PRL), mammary gland (produced within the mammary epithelial cells), or PRL variants of immune cell origin (that modulates the immune system). (Gellersen,1989; Andersen 1990; Lkhider, 1996; Kurtz,1993; Gala, 1994, Montgomery,1990; Ben-Jonathan 1996; Yu-Lee LY 1997)