Endocrinology Book



Aka: Prolactin, Serum Prolactin
  1. See Also
    1. Hyperprolactinemia
    2. Pituitary Gland
  2. Physiology
    1. Prolactin is a Protein synthesized and secreted by Lactotrophs (acidophil cells) in the anterior pituitary
      1. Stimulation (releasing factors)
        1. Vasoactive intestinal polypeptide (VIP)
        2. Thyroid Releasing Hormone (TRH, short-term factor only)
        3. Estrogen
        4. Postulated, specific Prolactin releasing Hormone (as of 2022, not identified)
      2. Inhibition
        1. Hypothalamic Dopamine (Prolactin Inhibiting Factor or PIF)
    2. Prolactin Characteristics
      1. Polypeptide Hormone with 198 Amino Acids
      2. Resembles Human Growth Hormone (hGH)
      3. Resembles Human Placental lactogen (hPL)
    3. Prolactin Effects
      1. Prolactin stimulates milk secretion into the Breast alveoli in pregnancy and Lactation
      2. Oxytocin stimulates myoepithelial cells to contract, expressing Breast Milk from the nipple
      3. Prolactin response assumes prior Breast development
        1. Breast ducts, fat and stroma develop with Estrogen exposure
        2. Breast glands, alveoli and secretory tissues develop with Progesterone exposure
    4. Prolactin increases with infant Breast Feeding
      1. Increases with each Breast Feeding episode
      2. Prolactin levels gradually level off after the first few months of regularly Breast Feeding
      3. Prolactin decreases to normal within 1-2 months of stopping Breast Feeding
  3. Pathophysiology
    1. See Hyperprolactinemia
  4. Technique: Preparation for lab draw
    1. Fasting level drawn before noon
    2. No Breast stimulation in last 48 hours
  5. Interpretation: Normal Levels
    1. Adult: <20 ng/ml
    2. Newborn: 100 to 300 (falls below 20 after 6 weeks)
    3. Pregnancy
      1. First Trimester: <80 ng/ml
      2. Second trimester: <160 ng/ml
      3. Third Trimester: <400 ng/ml
    4. Lactation
      1. Initially (<3 months postpartum)
        1. First week: 100 ng/ml basal level
        2. First 1-2 months: 50 ng/ml basal level
        3. Suckling raises Prolactin 10-20 fold above basal
      2. Later (3-6 months postpartum)
        1. Basal rates approach non-pregnant levels
        2. Suckling may double basal level
    5. References
      1. Bakerman (1984) ABCs of Lab Data, p. 342
  6. Interpretation: Increased Prolactin > 20 ng/ml
    1. See Hyperprolactinemia

Prolactin (C0033371)

Definition (CHV) milk producing hormone
Definition (CHV) milk producing hormone
Definition (CHV) milk producing hormone
Definition (CHV) milk producing hormone
Definition (NCI) Human prolactin (227 aa, 26 kDa precursor) is encoded by the human prolactin (PIT1) gene. This secreted lactogenic glycoprotein is expressed in both anterior pituitary lactotropes and the decidual endometrium. It acts primarily on the mammary gland and, in synergy with estrogen, induces progesterone release by corpus luteum cells to render the uterine mucosa suitable for implantation.
Definition (NCI_NCI-GLOSS) A hormone that is made by the pituitary gland (a pea-sized organ in the center of the brain). Prolactin causes a woman's breasts to make milk during and after pregnancy, and has many other effects in the body.
Definition (MSH) A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.
Definition (CSP) glycoprotein hormone secreted by the anterior pituitary; in mammals it stimulates the production of milk and assists in maintaining the corpus luteum.
Concepts Hormone (T125) , Amino Acid, Peptide, or Protein (T116) , Pharmacologic Substance (T121)
MSH D011388
SnomedCT 70454002, 82166002
LNC LP70338-6, LP14688-3, MTHU003168
English Hormone, Pituitary Lactogenic, Hormone, Pituitary Mammotropic, Lactogenic Hormone, Pituitary, Mammotropic Hormone, Pituitary, Mammotropin, Pituitary Lactogenic Hormone, Pituitary Mammotropic Hormone, Prolactin, luteotropin, LTH (luteotropic hormone), luteotropic hormone, mammary stimulating hormone, Lactogenic hormone, Prolactin [Chemical/Ingredient], lth, prolactins, lactogenic hormone, LTH, prolactin, PROLACTIN, PRL (Prolactin), Prl - Prolactin, Prolactin preparation, Prolactin (substance), Prolactin preparation (product), Prolactin preparation (substance), PRL
Swedish Prolaktin
Czech prolaktin
Finnish Prolaktiini
French Lactostimuline, Mammotropine, Mammotrophine, PRL (Prolactin), Hormone galactogène, Prolactine
Italian PRL (Prolattina), Ormone pituitario lattogenico, Mammotropina, Ormone pituitario della mammotropina, Prolattina
Japanese ラクトトロピン, 乳腺刺激ホルモン-下垂体性, 黄体刺激ホルモン, プロラクチン, ルテオトロピン, 下垂体性乳腺刺激ホルモン, 下垂体性泌乳刺激ホルモン, 乳汁分泌ホルモン, 乳腺刺激ホルモン, 催乳ホルモン, マンモトロピン
Spanish prolactina (producto), preparado de PL, preparado de prolactina (producto), preparado de prolactina, Hormona Mamotrópica Hipofisaria, Hormona-Lactógeno Hipofisaria, Hormona Mamotrópico-Pituitaria, Mamotrofina, Hormona Mamotrópica Pituitaria, Hormona-Lactógeno Pituitaria, Hormona Mamotrófica Pituitaria, Hormona Mamotrófico-Pituitaria, preparado de prolactina (sustancia), prolactina (sustancia), prolactina, Prolactina, Mamotropina
Polish Prolaktyna, Laktotropina, Hormon laktotropowy
Norwegian Prolaktin, Laktogent hormon, PRL
Portuguese Hormônio Lactogênico Hipofisário, Hormônio Mamotrópico Hipofisário, Mamotrofina, Hormônio Lactogênico Pituitário, Hormônio Mamotrópico Pituitário, Hormônio Mamotrófico Pituitário, Mamotropina, Prolactina
German Mammotropin, Prolactin, Lactogene Hormone, hypophysäre, Mammotrope Hormone, hypophysäre
Derived from the NIH UMLS (Unified Medical Language System)

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