Where is prolactin, a hormone produced by the pituitary (Pit) gland, primarily synthesized?

From the Guidelines

Prolactin is primarily produced in the anterior pituitary gland, which is located at the base of the brain.

Production and Regulation of Prolactin

Prolactin is secreted by specialized cells called lactotrophs. While the pituitary is the main source, prolactin can also be produced in smaller amounts by other tissues in the body, including the uterus, breast tissue, immune cells, brain, and placenta during pregnancy 1.

Key Points About Prolactin Production

• The release of prolactin from the pituitary is mainly regulated by dopamine from the hypothalamus, which inhibits its secretion.
• When dopamine levels decrease, prolactin secretion increases.
• This hormone is best known for stimulating milk production in women after childbirth, but it also has other functions in both men and women, including roles in reproductive function, immune regulation, and metabolism.
• Abnormal prolactin levels can lead to conditions such as hyperprolactinemia, which may cause symptoms like irregular menstrual cycles in women and decreased libido or erectile dysfunction in men.

Treatment of Prolactin-Related Conditions

In the context of treating prolactinomas, dopamine agonists like cabergoline are often used to reduce prolactin levels and shrink tumor size 1.

• Cabergoline has been shown to be effective in normalizing prolactin levels and improving symptoms in patients with prolactinomas.
• The treatment of prolactin-related conditions should be individualized and based on the specific needs and circumstances of each patient.

From the FDA Drug Label

The secretion of prolactin by the anterior pituitary is mainly under hypothalamic inhibitory control, likely exerted through release of dopamine by tuberoinfundibular neurons. The production of prolactin occurs in the anterior pituitary 2.

From the Research

Prolactin Production Sites

• Prolactin is primarily produced in the anterior pituitary gland, specifically by lactotroph cells in the adenohypophysis region 3, 4, 5, 6.
• In addition to the pituitary gland, prolactin is also produced in various extrapituitary sites, including:
  • The central nervous system 3, 5.
  • The immune system 3.
  • The uterus and its associated tissues of conception 3.
  • The mammary gland itself 3, 4.
  • The placenta, which is one of the most important organs secreting prolactin 4.
  • Lymphocytes, epithelial cells of lactating mammary glands, breast cancer cells of epithelial origin 4.
  • Decidua, prostate, skin, and possibly the brain 5.