Pituitary Flashcards
Which side of the pituitary contains the portal venous system?
Anterior pituitary
What is the gland axis from the hypothalamus to the peripheral tissues?
Hypothalamus -> Either GHRH (+) or Somatostatin (-) ->
Anterior pituitary -> GH ->peripheral tissues
What is the gland axis from the hypothalamus to the thyroid?
Hypothalamus -> TRH -> Anterior pituitary -> TSH -> Thyroid (T3 and T4)
What is the gland axis from the hypothalamus to the adrenal cortex?
Hypothalamus -> CRH -> Anterior pituitary -> ACTH -> Adrenal cortex -> Glucocorticoids
What is the gland axis from the hypothalamus to the gonads?
Hypothalamus -> GnRH -> Anterior pituitary -> FSH, LH -> Gonads -> Estrogen, progesterone, testosterone
What activates receptors associated with JAK/STAT pathway?
GH and prolactin
Dimeric protein hormones sharing a common alpha chain
Activate GPCRs
TSH, FSH, LH
Single-chain peptide, Activates a GPCR
ACTH
Recombinant human IGF-I drug
Used in treatment of severe IGF-I deficiency
Mecasermin
Growth hormone antagonists such as octreotide and Lanreotide are what analogs?
Somatostatin
What is a GH receptor antagonist
PEG derivative of a mutant GH and binds to GH receptor but blocks signal transduction
Pegvisomant
In women: Directs ovarian follicle development and stimulates the conversion of testosterone to estrogens
In men: Regulates spermatogenesis and stimulates the conversion of testosterone to estrogens
Follicle-stimulating hormone (FSH)
In women: Stimulates androgen production in the follicular phase. Controls estrogen and progesterone production in the luteal phase
In men: Stimulates androgen production
Luteinizing hormone (LH)
Produced in the placenta during pregnancy, nearly identical with LH (binds LH receptors), controls estrogen and progesterone production during pregnancy
Human chorionic gonadotropin (hCG)
FSH, LH, and hCG are all what type of proteins?
heterodimeric
hMG, first commercial gonadotropin product
extracted from the urine of postmenopausal women
Mixture of FSH and LH
Lower potency than purified FSH or LH
Menotropins
FSH purified from the urine of postmenopausal women
LH activity is removed during purification
Urofollitropin (uFSH)
Recombinant forms of FSH
Identical in amino acid sequence with FSH
Differ from each other and uFSH in carb chains
Considerably more expensive than uFSH
Follitropin alpha and beta
Recombinant form of LH
Approved for use in combo with follitropin alpha for stimulation of follicular development in infertile women with LH deficiency
Discontinued
Lutropin alpha
What is the synthetic analogs of GnRH suffix?
-relin
GNRH stimulates the production and release of ___ & ____ at what what point?
GNRH stimulates the production and release of LH & FSH only when its secretion is pulsatile
Nonpulsatile administration of GnRH inhibits the release of ___ & ____ in both women and men, resulting in __________
Nonpulsatile administration of GnRH inhibits the release of LH & FSH in both women and men, resulting in hypogonadism
Continuous treatment with GnRH agonist suppress what from being released?
Suppression of gonadotropin release
GnRH receptor antagonist have what suffix?
-relix
What inhibits the secretion of prolactin?
Dopamine
Hyperprolactinemia inhibits what from being released?
Inhibition of GnRH release
Vasopressin and oxytocin are found where?
posterior pituitary
Released by the posterior pituitary in response to rising plasma tonicity and falling blood volume.
Physiological functions include antidiuretic and vasopressor activity.
Vasopressin
GPCR that increases cytosolic Ca levels upon activation
Found on vascular smooth muscle cells
mediates vasoconstriction
V1 receptor
GPCR that increases cAMP levels upon activation
Found in renal tubule cells
Increases the number of aquaporins on the cellular membrane (water resorption)
V2 receptor
Vasopressin clinical uses
Pituitary diabetes insipidus, nocturnal enuresis
Major Adverse effects to vasopressin
water intoxication
Used to treat hyponatremia (associated with acute heart failure)
Vasopressin antagonist
Non-peptide antagonist of V1 and V2 receptors; intravenous
Conivaptan
Selective V2 receptor antagonist; oral
Talvaptan
Vasopressin antagonist have what suffix?
(-vaptan)
Acts through a GPCR
Induction and stimulation of labor, control of uterine hemorrhage after delivery, and enhancement of milk ejection
Oxytocin (Pitocin, Syntocinon)
Adverse effects of oxytocin
Excessive uterine contraction, activation of vasopressin receptor by overdose of oxytocin
