Prolactin
Overview
Prolactin measures a peptide hormone secreted by anterior pituitary lactotroph cells that primarily stimulates mammary gland development and milk production during pregnancy and lactation. It also influences reproductive function, immune regulation, and osmoregulation through widespread tissue receptors. Elevated levels (hyperprolactinemia) indicate prolactinoma, stalk compression, medications, or hypothyroidism; low levels rarely cause clinical symptoms. Clinically, prolactin testing evaluates galactorrhea, amenorrhea, infertility, and pituitary mass effects.
Clinical Use Cases
- Diagnosing prolactinoma and other pituitary adenomas.
- Evaluating galactorrhea-amenorrhea syndromes.
- Monitoring dopamine agonist therapy response.
- Assessing pituitary stalk compression or trauma.
Specimen Types
- Serum.
- Plasma (EDTA or heparin).
Measurement Methods
- Chemiluminescent immunometric assay.
- Electro-chemiluminescent immunoassay.
- Enzyme-linked immunosorbent assay.
Test Preparation and Influencing Factors
- Collect 2-4 hours post-awakening; avoid venipuncture stress.
- Tricyclic antidepressants, antipsychotics, and metoclopramide elevate levels.
- Macroprolactin (antibody-bound) causes pseudohyperprolactinemia.
- Pregnancy, nipple stimulation, and exercise cause physiologic elevations.
Synonyms
- Luteotropic hormone.
- Lactogenic hormone.