Prolactin

DESCRIPTION:
Patients must be in a relaxed state (free from physical and emotional stress). Additionally, before blood collection, any stress, palpation of the breasts, breast surgery, or intake of interfering medications should be avoided. The blood sample should be taken 1–2 hours after waking. Blood is collected between 8 and 10 AM. Prolactin is a polypeptide hormone with a molecular weight of 22,000 daltons and consists of 198 amino acids. Prolactin is secreted by the pituitary gland. The primary role of prolactin is to control milk production after childbirth. In addition to regulating the formation and secretion of milk in the breast during lactation, prolactin also influences the regulation of the reproductive cycle and affects fetal and maternal metabolism during pregnancy. In men, prolactin impacts water and electrolyte metabolism via the adrenal cortex and affects the function of the gonads (prostate, seminal vesicles) and testes. Prolactin is secreted in pulses (circadian rhythm). The highest levels of prolactin are secreted during nocturnal sleep, and the lowest at the moment of waking. A sudden increase in prolactin secretion occurs 60–90 minutes after the onset of sleep.

DETERMINATION:
Method of determination: ECLIA. The sample for analysis is serum or plasma (EDTA, Li-heparin). The sample is stable for 14 days at 2–8°C, and 6 months at -20°C.

RESULT:
The reference interval depends on sex, age, and the method of determination. The reference interval is displayed on each validated report.