Hypothalamus and Pituitary Flashcards
Half life of steroid hormones
Hours
Half life of amines
Seconds
Half life of peptides
Minutes
All hypothalamic hormones are peptides except:
Dopamine (amine)
Somatostatin inhibits:
GH release from anterior pituitary
Dopamine inhibits:
PRL release from anterior pituitary
Effects of GH
Increases gluconeogenesis, decreases glucose uptake in muscles, increases glucose uptake in brain, increases lipolysis, increases bone and soft tissue growth
Symptoms of GH excess
Prominent supraorbital ridge, coarsening of facial features, prognathism, enlarged tongue, thick skin, sweating, acne, increased spaces between teeth, spade like hands, snoring, disrupted sleep, joint pains, lethargy, tingling
Complications of GH excess
HT, diabetes, CTS
Hypersecretion of what often occurs with GH hypersecretion?
PRL
also hypopituitarism
When is GH high and when is it low?
High when sleeping/during day, in puberty
Low in pregnancy
Test for acromegaly
OGTT (no suppression of GH)
IGF-1, visual fields useful
MRI
Pituitary function tests
Treatment of acromegaly
Surgery
Radiotherapy
Dopamine agonists: Bromocriptine/Cabergoline
Somatostatin receptor agonists: Octreotide (GI side effects, gastritis, gall stones)
GH antagonists: Pegvisomant
Causes of hypopituitarism
Pituitary tumour, radiation, infection, trauma, immunological, mets
Treatment of hypopituitarism
Testosterone
Steroids
Thyroxine