Feedback Loop: Prolactin (PRL)
Authors: Nicola Adderley Reviewers: Andrea Kuczynski Bernard Corenblum* * MD at time of publication
Abbreviations:
TRH: Thyrotropin Releasing Hormone
DA: Dopamine
GnRH: Gonadotropin Releasing Hormone FSH: Follicle Stimulating Hormone
LH: Luteinizing Hormone
Note:
• PRL levels exhibit diurnal, menstrual, and age-related variation
• TRH has a stimulatory effect on PRL release; however, dopamine is the principal regulator of PRL secretion
Alveolar Cells of Breast Ducts
Milk production and release
Lactation
TRH
Suckling stimulus (via spinal afferents)
+
+
Hypothalamus + (arcuate nucleus)
DA
–
Anterior Pituitary Gland Lactotrophs
Uterus, immune cells, breast tissue, prostate
PRL
Hypothalamus
↓ GnRH secretion ↓ FSH/LH
↓ estradiol in females, ↓ testosterone in males
Limbic System
↓ libido
Immune System Organs
Promotes proliferation and maturation of immune cells
Oxytocin
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published November 19, 2018 on www.thecalgaryguide.com