Mod 1 lecture 1: hypothalamic-pituitary-gonadal axis Flashcards
what hormones does the hypothalamus release
GHRH
CRH
TRH
GnRH
(PRH;?TRH)
what are inhibiting hormones secreted by hypothalmus
somatostains (GHIH and TSH)
Dopamine (PIH)
what does GH stimulate
liver and increases somatomedins
what is another name for growth hormone
somatotropin
what tissues does GH target
bone, adipose, liver, muscle and growth plates
what are the growth hormone release modulators
somatotropin (genotropin, humatrope)
octreotide (sandostatin)
Pegvisomant(somavert)
what is somatropin
synthetic somatotropin (human GH)
what are the indications for somatropin
GH deficiency
Growth failure (turner syndrome, Noonan syndrome, prader-willi syndrome)
HIV patients with cachexia
what are the AE of somatropin
pain at injection side
edema
arthralgia and myalgia
nausea
glucose tolerance: insulin insensitivity
*warning:
do not use in pediatric patients with closed epiphyses
increased ICP
What is somatostatin
inhibitory hormone of GH
Hypothalamus:
-acts on anterior pituitary gland
-binds to pituitary GHRH receptors
-suppresses GH and TSH release
GI tract: supresses secretions and motility
What is Octreotide
long-acting synthetic somatostatin analog - GH release suppression
DOA: 12hrs to 6 weeks
GH release modulator
what are the inidcations of Octreotide
acromegaly
Severe diarrhea caused by carcinoid tumor
bleeding esophageal varices
what are the AE of octreotide
CVS: bradycardia and conduction distrubances
GI: diarrhea, abdominal pain, flatulance, nausea and streatorrhea
What is Pegvisomant
GH receptor antagonist - modified HGH with receptor blocking-properties
what are the indications for Pegviosomant
acromegaly that is refractory to other pharmacological surgical or radiological intervention
What are the AE of Pegviosomant
GI: diarrhea and nausea
CNS: pain
Hepatic: abnormal hepatic function tests
What is ACTH
corticotropin - naturally occuring hormones
What is ACTH
corticotropin - naturally occuring hormones
anteriro pituitary homrone
stimulates steroid biosynthesis
what is cortosyn
cosyntropin - sythesized ACTH hormon
What is CRH
corticotropin - releasing homrone
hypothalamic hormone
regulates synthesis and release of ACTH
What is Cosyntropin
synthtic ACTH
full biological potency
stimulates adrenal cortex to secrete adrenal steroids (cortisol), androgenic substances, and a small amount of aldosterolne
what are the indications for Cosyntropin
diagnostic tool for ACTH stimulation test
screening for adrenocorticosteroid deficiency - primary adults insufficiency (hypoadrenaliism - addisons disease)
What are the AE of Cosyntropin
excess glucocoriticoid toxicities:
HTN, peripheral edema, hypokalemia, osteoporosis
What is GnRH
gonadotropin-releaseing hormone
secreted from the hypothalamus
binds to receptors in anterior pituitary gland
release in gonadotropins (FSH and LH)
what is essential for gonadotropin rlease
pulsatile secretion
what results in the down regulation of GnRH receptors and suppression of gonadotropin release
continuous secretion
what are the indicatiosn for suppression of gonadotropin production
prostate cancer
endometriosis and uterine myomas (fibroids)
precocious puberty
infertility treatment: controlled ovarian stimulation, suppression of LH surge and ovulation
suppressing sex hormones in transgender people
what are the adverse effects of FSH-LH release modulators in females
generalized menopausal symptoms
ovarian cysts
what are the AE of FSH-LH release modulators in males
transient increase in testosterone
hot flashes, sweats, edema, gynecomastia, decreased libido, decreased HCT, and bone density
What is Leuprolide (lupron) used for
used to treat prostate cancer, breast cancer, endometriosis, uterine fibroids and early puberty
can delay the onset of puberty in transgender youth prior to initiation of HRT
can be used to delay or prevent early ovulation in order to allow for the development of mature eggs for retrieval in IVF cycles
What is goserelin (zoladex)
used to suppress production of sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer
what is nafarelin (synarel)
used in the treatment of endometriosis and early puberty
what is histrelin (vantas)
used to treat advanced prostate cancer in adults,. will reduce level of testosterone
what is Prolactin
hormone secreted from the anterior pituitary
stimulates and maintains lactation
decreases libido
what regulates prolactin
tonic inhibition by dopamine - dopamine antagonists (antipsychoatics) increase prolactin secretion
TRH also stimulates the release of prolactin
what is Bromocriptine
dopamine receptor agonist that treats hyperprolactinemia, parkinsons disease
what is cabergoline
first-line agent in the management of prolactinomas due to its higher affinity for D2 receptor sites, less severe side effect and more convenient dosing schedule than bromocriptine
what are the indications for bromocriptine and cabergoline
D2 receptor agonists - suppress prolactin release
Lactotroph adenomas (prolactinomas) - hyper prolactemia
what are the affects that Bromocriptine has on T2DM
acts on circadian neuronal activities in the hypothalamus to reset an abnormally elevated hypothalatic drive for increase plasma glucose, free fatty acids, and triglycerides in insulin-resistant patients
minimally effecting at decreasing A1C (0.5%)
what are the AE of bromocriptine and cabergoline
CNS: HA, Dizziness, psychosis
GI: nausea
what hormones are secreted by posterior pituitary gland
oxytocin
vasopressin
desmopressin
what tissues are targeted by oxytocin
uterus and breast - contraction and milk expression
what tissues are targeted by vasopressin (aka ADH)
Nephron (CT and CD) - V2 receptors - water reabsoprtion and hyponatremia
vascular smooth muscle - v1 receptors - vasoconstriction
what is the use of oxytocin
stimulate uterine contraction
labor induction
postpartum hemorrhage
what are the AE of oxytocin
hypotension and arrhythmias
fluid retention (ADH effects)
placental abruption or uterine rupture
fetal distress and death
what is vasopressin
synthetic vasopressin (ADH analog)
stimulates arginine vasopressin receptors (AVP)
desmopressing has selective V2 activity
what are the indications for vasopressin
central diabetes insipidus (absence of ADH)
nocturnal enuresis
what are the AE of Vasopressin
water intoxication and hyponatremia
HA, bronchconstriction and tremor
*warning:
caution when using vasopressin in patients with CAD, epilepsy and asthma
Nasal spray has been linked to increased seizures in children
