Prolactin Mr. Wiedert Paige Hopper
Production of Hormone • Prolactin is a hormone produced by the pituitary gland, the pea-sized gland near the base of the brain that controls metabolism, growth, and sexual development. Even though prolactin is produced in small amounts in males and females its main purpose is to obtain milk during a women's pregnancy.
Its Role • Its role in enabling female mammals to produce milk • Prolactin is secreted from the pituitary gland in response to eating, mating, estrogen treatment, ovulation, and nursing.
When is Hormone Most Active? • Pregnant women have high levels of prolactin, which helps make breast milk. During pregnancy, prolactin levels increase by 10 to 20 times. After the baby is born, prolactin stays high if you are breast-feeding. In women who do not breast-feed, prolactin levels return to normal soon after they give birth. After months of breast-feeding, prolactin levels may also return to normal levels even if you still breast-feed. • The pituitary glands of men and nonpregnant women also make prolactin but it is not clear what it does in the body for these people.
Normal Levels • Males: 2 - 18 ng/mL • No pregnant females: 2 - 29 ng/mL • Pregnant women: 10 - 209 ng/mL • Note: ng/mL = nanograms per milliliter
Abnormal Results Lead too… Certain medications can also raise prolactin levels, including: Antidepressants Butyrophenones Estrogens H2 blockers Methyldopa Metoclopramide Phenothiazines Reserpine Risperidone Verapamil • People with the following conditions may have high prolactin levels • Chest wall trauma or irritation • Hypothalamic disease • Hypothyroidism • Kidney disease • Pituitary tumor that makes prolactin(prolactinoma) • Other pituitary tumors and diseases
How are Atypical Amounts Treated • Lactotroph adenomas (prolactinomas) are benign (non-cancerous) tumors of the pituitary gland that produce prolactin and thereby cause higher than normal blood prolactin concentrations. They can cause symptoms, either when the high blood prolactin concentration interferes with the function of the ovaries or testicles or, less commonly, when the adenoma grows large enough to compress nearby structures in the head, such as the nerves to the eyes. • Prolactinomas occur in both men and women but are more commonly diagnosed in women who are less than 50 years than in older women or men. • Prolactinomas can usually be treated successfully with medication alone. Medication lowers the prolactin level in the blood substantially, often to normal, and also usually reduces tumor size. However, a minority of these tumors do not respond to medication and must be treated with surgery or, less
Steroid or Protein? • Protein
Target Cell and its Entery • Prolactin production is inhibited by prolactin–inhibiting hormone ( PIH ) the neurotransmitter dopamine. The hypothalamus also secretes a prolactin releasing hormone, but the identity of this prolactin–releasing factor ( PRF ) is a mystery. Circulating PRL stimulates PIH release and inhibits the secretion of PRF . • Prolactin, estrogens, progesterone, glucocorticoids, pancreatic hormones, and hormones produced by the placenta cooperate in preparing the mammary glands for secretion, and milk ejection occurs only in response to oxytocin release at the posterior lobe of the pituitary gland.
Can it be Synthetically Replaced? • Most pituitary hormones can be replaced indirectly by administering the products of the effector glands: hydrocortisone (cortisol) for adrenal insufficiency, levothyroxine for hypothyroidism, testosterone for male hypogonadism, and estradiol for female hypogonadism (usually with a progestogen to inhibit unwanted effects on the uterus). Growth hormone is available in synthetic form, but needs to be administered parenterally (by injection).
Work Cited • http://kidshealth.org/parent/system/medical/test_prolactin.html • http://www.nlm.nih.gov/medlineplus/ency/article/003718.htm • http://www.uptodate.com/contents/high-prolactin-levels-and-prolactinomas-beyond-the-basics • http://en.wikipedia.org/wiki/Prolactin • http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/prolactin.gif