Rose: PRL Flashcards
What is the primary stimulus for PRL?
PRH
What is the inhibitory factor for PRL?
DA
What produces PRL?
mammotrophs
PRL acts on what type of receptor?
JAK/STAT dimer family>
trxn events
What is the difference between PRL long and short form recpetors
short- negative regulators, soak up ligand and keep it from acting through long receptor
long- active receptor, stimulatory form
What are the physiologic effects of PRL?
- immunity and autoimmunity
- breast development during pregnancy
- milk secretion
VERY hi levels when nursing
How is PRL regulated?
Hypo secretes DA to tonically INHIBIT PRL
Acts on D2 receptors on pituitary lactorophs
What happens if the pituitary portal system is blocked/severed?
PRL secretion INCREASES while most other hormones DECREASE
How does hypersecretion of PRL affect Males?
suppresses GRH>
impotence
How does hypersecretion of PRL affect females?
suppresses GRH> ammenorrhea, infertility
acts on receptors in breast tissue> galactorrhea
How do you tx a hyperprolactinemia tumor?
DA agonists
What is cabergoline?
Preferred dopamine agonist
has higher efficacy in normalizing prolactin levels, as well as a higher frequency of pituitary tumor shrinkage
What are SE of cabergoline?
nausea, vomiting, dizziness and orthostatic hypotension may occur
discouraged use to prevent post-partum lactation because of increased incidence of strokes and psychiatric manifestations
