Santos's Lectures Flashcards
Anterior Pituitary (adenohypophysis)
-INDIRECT connection w/ hypothalamus
Posterior Pituitary (neurohyphysis)
-DIRECT connection w/ hypothalamus
which 2 hypothalamic factors do NOT have any inhibitory factors?
-CRH and GnRH
Growth Hormone (GH) -aka somatotropin
- effects mediated through IGF-1 and IRS-1
- measure IGF-1 levels to look at GH levels***
-used for BONE and muscle growth, decrease fat
-pulsatile secretion at night
-
what is an inhibitor of GH used for acromegaly and gigantism?
-somatostatin and dopamine
what are the 2 somatostatin analogs?
-Octreotide and Lanreotide
Pegvisomat
-GH receptor antagonist -> blocks receptor activation but not secretion
what condition is associated w/ failed IGF-1 release?
Laron Dwarfism
GH vs IGF-1
- GH -> REDUCES insulin sensitivity -> diabetes
- IGF-1 -> insulin-like effects -> GLUT4 transporters
Somatropin
- rhGH
- targets GH receptor
- used for Noonan, prader-willi, turner syndromes
- used w/ wasting syndromes in HIV ptxs or short bowel syndrome
Mecasermine
- IGF-1 analog -> IGF-1 production at GH receptor sites
- AE -> HYPOGLYCEMIA
Prolactin
- blocked by DOPAMINE -> binds to D2 receptors on lactrotrophs
- TRH and VIP stimulate release
- lactation in mammary gland -> growth of ducts/lobules
- NOT under feedback control of peripheral hormones
Bromocriptine
-also pergolide, cabergoline, quinagolide
- dopamine receptor agonists -> blocks HYPERPROLACTINEMIA
- bind to D2 receptors on lactotrophs
-also used for Parkinson’s disease
GnRH aka Gonadorelin
-release of LH, FSH
-used for hypogonadotropic hypogonadism
-used for INFERTILITY
-
function of LH
- target theca cells -> androstenedione
- target leydig cells -> testosterone
function of FSH
- target granulosa cells -> growth of follicle and activate aromatase
- target Sertoli cells -> sperm maturation
what enzyme converts androgens to estrogen?
aromatase
intermittent (pulsatile) vs. continuous secretion of GnRH
- pulsatile GnRH release -> increase LH, FSH
- continuous GnRH release -> inhibit LH, FSH
analogs of GnRH
- Leuprolide
- GnRH
- Goserelin
- Nafarelin
- Triptorelin
-NOT used if pregnant
antagonists of GnRH
- Ganarelix
- Cetrorelix
- Abarelix
hCG
- made in placenta
- mimics LH -> acts on LH receptor
- diagnosis of PREGNANCY**
ACTH
-made from POMC** -> produces cortisol in adrenal cortex
Cosytropin
-synthetic form of ACTH
TRH
- produce T3 (more acitve) and T4 (high levels, long lasting)
- treat hypothyroidism