Prolactin

Prolactin is hormone produced by pituitary gland. Pituitary gland is major hormone secreting gland located at the base of the brain. Prolactin is referred to as the ‘milk hormone’. Its major role is in the secretion of milk during lactation, hence the name prolactin. However, it also plays major role in reproductive system and immune system.

Though majority amount of prolactin is released by pituitary gland, some amount is also released by uterus, prostrate, adipose tissue, immune cells and breasts. Secretion on prolactin is controlled by estrogen. More estrogen triggers more prolactin. For this reason, prolactin levels are high during pregnancy, which help sustain the pregnancy. Another hormone known as dopamine also controls prolactin production in negative manner i.e. less dopamine means higher prolactin secretion and vice-a-versa.

• Milk production and the development of mammary glands within breast tissues.
• With help of other hormones, helps sustain pregnancy
• Apart from these it regulates behaviour, the immune system, metabolism and reproductive system
• Role of prolactin in males in unclear, however high prolactin causes low sex drive and erectile dysfunction

• In men and non-pregnant women levels of prolactin are negligible. High levels of prolactin can be due to pituitary tumour (prolactinoma), injury to breast tissue, injury to hypothalamus (part of brain that controls pituitary), certain anti-depressants or eating disorders.
• Prolactin levels test is most often used to:
• Diagnose a prolactinoma (a type of tumour of the pituitary gland)
• Diagnose cause of a woman's menstrual irregularities and/or infertility
• Help find the cause of a man's low sex drive and/or erectile dysfunction

If you have prolactinoma (tumour of pituitary gland). General symptoms of high prolactin include:

• Production of breast milk if you are not pregnant or breastfeeding
• Nipple discharge
• Headaches
• Changes in vision

Some of the other symptoms of prolactinoma differ in men and women.

• Symptoms in men:
  • Breast enlargement
  • Nipple discharge
  • Low sex drive
  • Erectile dysfunction
• Symptoms in women:
  • Irregular periods
  • Early menopause (before 40)
  • Infertility
  • Brest tenderness
  • Menopausal symptoms hot flashes and vaginal dryness

Requirement:  No special preparation is required before you take the test. However, you may be advised any other test along with it that might require you to fast (not eat and drink) for 8-12 hours before the test. It is always advisable to ask your doctor regarding the same.

 Reference range:

 Male: 2 to 18 ng/mL

Female:

Pregnant: 9.7 - 208.5 ng/ml

Postmenopausal: 1.8 - 20.3 ng/ml

Interpretation:

 If your value falls outside the normal range, this doesn’t automatically mean you have a problem.  Many drugs or even recent injury can give high results. However, if you have very high levels, it could be sign of prolactinoma. This can lead to menstrual disturbances, estrogen deficiency and testosterone deficiency or unwanted lactation. It is usually treated with medicine. If your pituitary gland is not functioning fully ie. Hypopituitarism, your levels may be lower than normal range. Lower levels of prolactin usually do not need medical treatment.