park lecture 5 Flashcards
hormones produced by hypothalamus \
GHRH, SST, TRH, CRH, GNRH
Only hormone produced in hypothalamus that does not end in RH
SST
What are the 2 hypothalamic hormones that control the release of growth hormone
GHRH(stimulates)
SST (suppress)
What are some anterior pituitary hormones
gH, prolactin, TSH, FSH, LH, ACTH
Only anterior pituitary hormone not ending with H
prolactin
Know the hypothalamic precursor and the pituitary hormones
TRH-TSH
GNRH,SST- GH
GnRH- LH, FSH
CRH- ACTH
Group the pituitary hormones based on their structural similarity
Prolactin and GRH- Single chain proteins that activate JAK/STAT pathway
TSH, LH, FSH- Share common a-chain and activate GPCRs
Describe the functions of GH and IGF-1
GH stimulates the production of IGF-1, which has anabolic effects on muscle, catabolic lipid effects, and a reduction in insulin activity
Why does GH lower insulin activity in the body
Becuase IGF-1 has insulin activity
Difference between somatotropin and somatostatin
Somatostatin decreases GH secretion (statin), Somatotropin is the recombinant form of GH
What is somatotropin (rhGH)
The recombinant form of GH
recombinant form of IGF-1
Mecasermin
Mecasermin use
Used in case of non-responsiveness to GH, so it skips the GH and directly gives IGF-1
What is needed to maintain adequate half life of mecasermin
rhiGFBP-3 (recombinant human IGF binding protein 3
what does FSH do in women
Stimulates conversion of testosterone to estrogen (universally across genders)
directs ovarian follicle development
What does FSH do in men
Converts testosterone to estrogen
regulates spermatogenesis
what does LH do in women
stimulates androgen production in follicular phase
controls estrogen and progesterone production in luteal phase
What does LH do in men
Stimulates androgen production in men
What two gonadotropins are nearly identical and bind each others receptors
LH and HCG
with regard to alpha and beta chains, what is the relation between LH, FSH and HCG
All share the same alpha, but HCG and LH share the same B chain
Different gonadotropins used clinically names
menotropin
Urofollitropin
Follitropin a & B
Lutropin a
HCG
choriogonadotropin a
Explain what menotropin is
It is an HMG (human menopausal gonadotropin) that is a mixture of LH and FSH extracted from the urine of postmenopausal women.
Explain what urofollitropin is
Urofollitropin is the purified FSH from the urine of post menopausal women
LH is removed
What is the recombinant form of FSH
Follitropin a &b
What is the recombinant form of LH
Lutropin a
recombinant form of HCG
choriogonadotropin a
what is clomiphen
Clomiphen is a SERM that blocks negative feedback in pituitary and increases LH/FSH levels, promoting ovulation
Side effect of clomiphen
multiple births
_____stimulates the production and release of LH and FSH
GnRH
What do we mean by pulsatile GnRH release
GnRH will only stimulate the release of FSH and LH if it is released in a pulsatile fashion.
What will happen if the release of GnRH is not oulsatile
GnRH will inhibit release of FSH and LH in both men and women
Why does non-pulsatile release lead to inhibition of LH and FSH release
Receptors get desensitized
What is vasopressin
An anti diuretic hormone and vasopressin (constricts blood vessels)
where is vasopressin released from
Posterior pituitary
Vasopressin is released in response to
rising plasma tonicity (salty blood)
Falling blood volume
Physiological function of vasopressin
increase reabsorption of water from tubular filtrate
How does vasopressin increase reabsorption from tubular filtrate
Increases water permeability in cells in renal collecting tube. leads to increase in BV and decrease in urine
why is its name vasopressin
constricts blood vessels
Why does vasopressin contracting blood vessel help?
decrease in blood volume will lead to a drop in blood pressure. constricting BV will bring it up again
what is the difference between the two vasopressin receptors
V1- is in blood vessel. It is a GPCR that increases Ca2+, leading to vasoconstriction
V2- is in the kidneys, once activated, the number of aquaporins is increased, they get water from urine to blood.
Desmopressin receptor selectivity with regard to V1 and V2
Desmopressin has 4000 times V2 antidiuretic activity compared to V1.
adverse effects of vasopressins
water intoxication (hyponatremia)
Vasopressin (not desmopressin) should be used with EXTREME caution with people with CV diseases
Oxytocinn use
Uterine contraction during labor and delivery.
How does oxytocin stimulate contraction
Releases prostaglandins and leukotrienes that augment uterine contraction
Oxytocin role in lactation
Contracts myoepithelial cells in breast and ejects milk (ca2+ release)
at high concentration, oxytocin has a weak antidiuretic effect. why?
Similar structure with Vasopressor
Clinical uses of oxytocin
-Induction and stimulation of labor.
-Control of uterine hemorrhage after delivery
adverse effects of oxytocin
-excessive stimulation of uterine contraction before delivery (leads to uterine distress, uterine rupture)
-cross reactivity causes activation of vasopressin (fluid retention, hyponatremia)
