Flashcards in 7. Hypothalamic-pituitary hormones Deck (29):
increases ACTH , MSH , β- endorphin secretion
CRH is decreased in ( situation )
chronic exogenous steroid use
Dopamine function ( hypothalamic pituitary )
decreases prolactin and TSH secretion
dopamine antagonist example
dopamine antagonists can cause ( and why 0
glactorrhea due to hyperprolactinemia
increases GH secretion
GHRH analog ?
used to tread HIV lipodystrophy
increases the secretion of
GnRH is regulated by
prolactin ( negative)
GnRH under tonic ( continous ) secretion
it supresses HPA axis
GnRH under pulsatile secretion
leads to puberty, fertility
prolactin effect on hypothalamic pituitary axon
it supresses GnRH secretion
pituitary prolactinoma - symptoms
3. hypogonadism ( infertility, low libido)
1. Increases TSH secretion
2. Increases prolactin secretion
prolactin secretion is regulated by
1. TRH (positively )
2. dopamine ( negatively)
3. prolactin ( negatively by increasing dopamin secretion)
4. estrpgem and progesterone ( positevely, in pregnancy)
somatostain analogs are used to
somatostatin function ( on hypothalamic pituitary axon )
TSH is regulated by
1. somatostatin ( negatively)
2. TRH (positevely)
3. T3/T4 ( negatively, decrease sensitivity of TRH)
4. dopamine ( negatively )
action of antipsychotics on hypothalamic pituitary axon
dopamine antagonists ( induce prolactin secretion)
TRH vs Dopamine according to their action on axon
-TRH increases TSH and prolactin
-Dopamine decreases TSH and prolactin
What is the effect of thyrotropin-releasing hormone (TRH) on pituitary hormone secretion?
Stimulates thyroid-stimulating hormone (TSH) and prolactin secretion
What is the effect of corticotropin-releasing hormone (CRH) on pituitary hormone secretion?
Stimulates secretion of adrenocorticotropic hormone (ACTH), melanocyte-stimulating hormone (MSH), and β-endorphin
A 10-year-old boy, short for his age, is found to have growth hormone (GH) deficiency. High/low levels of which hormone(s) may cause this?
Low growth hormone–releasing hormone (GHRH) or high somatostatin decreases the level of growth hormone
A 50-year-old man is found to have a somatostatin-producing tumor. How does this affect pituitary hormone secretion?
Inhibits growth hormone (GH) and thyroid-stimulating hormone (TSH) secretion
A woman with visual defects is found to have a prolactinoma. How does the high prolactin affect secretion of other pituitary hormones?
Inhibits gonadotropin-releasing hormone (GnRH), which in turn decreases luteinizing (LH) and follicle-stimulating hormone (FSH) secretion
A postpartum woman wants to breastfeed, requiring high prolactin. What must happen to dopamine levels to allow this?
Dopamine levels must decrease because dopamine has an inhibitory effect on prolactin release
A woman goes from taking a small amount of a GnRH agonist several times a day to taking large amounts a few times a day. What does this do?
Tonic GnRH administration suppresses the HPA axis, and switching to a pulsatile schedule promotes puberty and fertility
You give a patient a new drug to treat his HIV-associated lipodystrophy. GH level increases as a result. What is the mechanism of action?
Tesamorelin is a GHRH analog