Acromegaly/Prolactinoma Flashcards
GH hormone causing amenorrhea and galactorrhea?
these are prolactin effects
1 GH acts on JAK STAT receptors
-same as PRL
so can cross activate
2 also - GH adenoma may release some PRL
3 and - acromegalic tumor - push on pituitary stalk - block dopamine - no PRL inhibition
inhibition of PRL
dopamine
TRH
stimulates PRL secretion
PRL
blocks LH at ovary and testes
positive tinel sign
of median nerve
-myxedema - GAG infiltrates
bony overgrowth and synovial thickening
- in acromegaly
HA worse with coughing, nausea, worse upon arising
marker for mass effect in brain
acanthosis nigricans
and skin tags
seen in epidermis overgrowth - IGF-1 effect (acromegaly)
increased head size
acromegaly
possibly cowdens
why order calcium in GH adenoma
suspected MEN
-may have parathyroid involvement as well**
serum GH 2 hours post 75g glucose
glucose should suppress GH level
if not - acromegaly**
inability to suppress GH to less than 1 ng/mL
why T4, TSH, and cortisol measured in GH adenoma
may compress other cell types
GH effects on glucose
1 produces lipolysis
- leads to increased gluconeogenesis
- increased conversion of lactate and glycerol to glucose
2 FFA block glucose uptake by muscle and fat cell
GH is slow acting counter regulatory hormone like cortisol
microadenoma with somatotroph mutation
cause of acromegaly
-mutation of alpha subunit of GTP-binding protein resulting in stimulatory Gs subunit
with increased cAMP producing GH secretion
causes of acromegaly
microadenoma
macroadenoma
ectopic GH - lung
acromegaly associations
1 - MEN 1
2 - carney complex
3 - mucune albright syndrome
