Hypothalamic and Pituitary Hormones Flashcards
dopamine aka
PROLACTIN-INHIBITING HORMONE
GHRH or GROWTH HORMONE RELEASING HORMONE aka
SOMATROPIN-RELEASING HORMONE
GROWTH HORMONE aka
SOMATROPIN
ACTH or adrenocorticotropic hormone aka
CORTICOPTROPIN
TSH aka
thyrotropin
two distinct components of the pituitary gland
adenohypophysis
neurohypohysis
connects hypothalamus and pituitary gland
hypothalamic or pituitary stalk
hormones that pass thru the pituitary portal stalk to stimulate the pituitary gland to release or inhibit hormone production
hypophysiotrophic hormones secreted by neurosecretory cells in the hypothalamus
hormones produced in the PPG will act
directly on target organs
PPG hormones secreted in response to stimulus
VASOPRESSIN/ ADH
OXYTOCIN
prolactin from APG acts
directly on mammary glands
hormone that acts both directly and indirectly
GROWTH HORMONE
hypothalamic and pituitary hormones are ALL
peptides
hormones of the posterior pituitary are stored in
granules
makes the hormone susceptible to destruction by proteolytic enzymes of the digestive tract
peptidyl nature
TRH may
increase levels of PROLACTIN causing galactorrhea
no pharmacologic preparation available
PROLACTIN
hormones used for diagnosing pituitary insufficiency
GHRH CRH TRH TSH ACTH
hormones released by the hypothalamus
TRH CRH GHRH GnRH Dopamine somatostatin
anterior pituitary gland hormones
TSH ACTH GH FSH, LH PRL GH
posterior pituitary gland relese the ff hormones
VASOPRESSIN / ADH
OXYTOCIN
steroid or steroid-like hormones are _____ in the circulation
protein bound
only the ____ form of steroid and steroid like hormones that is active and can enter the cell membrane
free
peptides cannot enter the cell membrane therefore they are
hypdrophilic
receptor for GH and PRL
Jak STAT
Januse kinase signal transducer and activator of transcription
receptor for GHRH, TSH, FSH, LH, ACTH, VASOPRESSIN
Gs
Gs function
stimulates adenylyl cyclase
receptor for SST and DOPAMINe
Gi
Gi function
inhibits adenylyl cyclase
GnRH, OXYTOCIN, VASOPRESSIN 1A & B receptor
Gq
Gq function
muscarinic receptor
2nd messenger for IP/DAG
SST or somatostatin aka
growth hormone-inhibiting hormone
SST is secreted by
the D cells of the stomach
the delta cells of the islets of Langerhan
somatostatin moa
inhibits secretion of GH, TSH, INSULIN, GLUCAGON, GASTRIN, and other GI hormones
use of somatostatin is limited due to
short duration of action
multiple effects esp in cho metabolism
rebound hypersecretion
SST analogs
OCTREOTIDE (Sandostatin)
LANTEOTIDE
receptors for OCTREOTIDE
SSt-2
selectivity of OCTREOTIDE to SST2 receptors have less
effect on insulin therefore less hyperglycemia
OCTREOTIDE preparation
50-200 mcg SC q8hr, once a month
indication for SST ANALOGS
acromegaly
GEP tumors such as carcinoid and gastrinoma
bleeding esophageal varices
SST analog dosage for acromegaly
initially 0.05 - 0.1 mg, SC q8-12 hr
max of 1.5 mg per day
gep tumor tx of sst analog dosage
initially 0.05 mgOD/BID
may gradually inc to 0.1-0.2mg TID
SST analog adverse effects
GIT 50%
Gallstones 20%
GH receptor antagonist
PEGVISOMANT
effect of PEGVISOMANT
blocks peripheral effects of GH ➡️ decrease IGF 1
PEGVISOMANT administration
daily via SC route
PEGVISOMANT Indication
px with acromegaly who do not respond to SST analogs
PEGVISOMANT AE
inc in tumor size- uncommon
changes in liver fxn tests
physiological fxn of GnRH
released in PULSATILE manner that controls the synthesis and release of FSH and LH
pharmacological fxn of GnRH
pulsatile: every 4hrs, stimulates GONADOTROPIN release
continuously: via injection, inhibits GONADOTROPIN RELEASE
cause of iNhibitory release of gonadotropin when released continuously
receptor desensitization
downregulation
changes in signaling pathways
GnRH analogs
LEUPROLIDE GOSERELIN NAFRELIN GONADORELIN HCL BUSERELIN
LEUPROLIDE preparation
7.5mg per month IM for prostatic cancer
q3months
1mg/day SC
GOSERELIN preparations
3.6 mg SC q28days
NAFARELIN preparation
nasal spray 200 mcg BID
not available!
uses (rare) of GnRH
pulsatile: pituitary stimulation in GnRH deficiency (male or female)
continuous: suppress gonadotropins
diagnostic
GnRH use for pituitary stimulation in GnRh deficiency addresses
male or female infertility or hypogonadism
suppression of gonadotropins through continous admin of gnRh is for
endometriosis central precocious puberty prostatic cancer and BPH uterine leiomyoma contraception ART