Prolactin: Function and Hyperprolactinemia

Reference Levels of Prolactin

Normal value: 2–25 ng/ml
Between 25–200 ng/ml there is a diagnostic uncertainty about the cause of hyperprolactinemia. Prolactin levels > 200 ng/ml speak in favor of a prolactinoma.

Prolactin is a polypeptide of 199 amino acids, which is released from the anterior lobe of the pituitary gland.

Pregnancy
Sucking (by the baby) on the nipple
Most probably, there is a prolactin releasing hormone (PRH), yet to be identified.
TRH, oxytocin, angiotensin II, serotonin, endorphin and adrenaline are promoting prolactin release.

Dopamine, also called prolactin-inhibiting hormone (PIH)
GHRH, endothelin-1, increased plasma osmolarity (prevention of dehydration of the breastfeeding mother)

Inhibition of ovulation (during lactation)

Prolactinoma (usually prolactin levels > 200 ng/ml)
Lack of prolactin inhibitory factor (PIF) = dopamine: Damage to the hypothalamus or pituitary tumors
Drugs: metoclopramide, estrogen-containing drugs, antidepressants, antipsychotics
Functional hyperprolactinemia: usually only moderately elevated prolactin levels are caused by stress, pregnancy and lactation, severe renal insufficiency or primary hypothyroidism.

Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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Dr. med. Dirk Manski
man...@urologielehrbuch.de