Hypothalamic and Pituitary Drugs

Question 1

MOA of cabergoline

Answer 1

dopamine-receptor agonist that suppresses prolactin production through D2 receptor.

Question 2

MOA of cetrorelix

Answer 2

decapeptide antagonists of GnRH receptors used in in vitro fertilization. Delay premature LH surge to delay ovulation and allow collection of ova. Follows FSH therapy.

Question 3

MOA of ganirelix

Answer 3

decapeptide antagonists of GnRH receptors used in in vitro fertilization. Delay premature LH surge to delay ovulation and allow collection of ova. Follows FSH therapy.

Question 4

MOA of gosarelin

Answer 4

agonist of GnRH used in treatment of prostate cancer. Initially increases LH, then decreases LH and testosterone dramatically due to receptor down-regulation

Question 5

MOA of menotropin

Answer 5

FSH and LH from urine of postmenopausal women that can be administered IM to treat infertility.
Can treat infertility in males also.

Question 6

ADE of menotropin

Answer 6

risk of multiple pregnancy

Question 7

MOA of octreotide

Answer 7

somatostatin analog. Much more potent than endogenous forms.

Question 8

ADE of octreotide

Answer 8

GI - diarrhea, nausea, abdominal pain

Question 9

MOA of somatotropin

Answer 9

generic name of all GH that is identical with hGH

Question 10

ADE of somatotropin

Answer 10

Children - few. Occasional intracranial hypertension, papilledema, visual changes, headache, nausea, vomiting.
*Contraindicated for 2 years after pediatric tumors because of leukemia risks

Men - increased muscle and bone, decreased fat
Adults - peripheral edema, carpal tunnel syndrome, arthralgia, and myalgia

Question 11

Which anterior pituitary hormones are somatotropic?

Answer 11

GH and PL

Question 12

Which hormones are glycoproteins? What gives glycoproteins their different functions?

Answer 12

TSH (thyrotropin), LH, FSH, and hCG (from placenta).

Common alpha subunit, differing beta subunit gives differing actions.

Question 13

Which hormones are POMC (proptiomelanocortin) derived?

Answer 13

ACTH and MSH

Question 14

Which hormones do somatostatins negatively regulate?

Answer 14

insulin, glucagon, TSH and GH

Question 15

Which hormone does dopamine inhibit?

Answer 15

PL and TSH through D2 receptor.

Question 16

Is insulin injection a valid means for diagnosing GH deficiency?

Answer 16

yes. Insulin will cause hypoglycemia which should stimulate GH release.

Question 17

What is the second messenger system for GH?

Answer 17

tyrosine kinase (JAK2)

Question 18

Will a child with IGF-1 deficiency respond to hGH?

Answer 18

NO. These children usually have IGFBP deficiency also. Must give mecasermin, a complex of hIGH-1 and hIGFBP-3

Question 19

What hormone urine level can be measured to predict ovulation? What about pregnancy?

Answer 19

LH levels spike 36 hours before ovulation.

hCG levels spike after fertilization

Question 20

Where does LH act?

Answer 20

Leydig cells of men and thecal cells in women to produce respective hormones, testosterone and androgens.

Question 21

Where does FSH act?

Answer 21

on sertoli cells (men) and granulosa cells (women) to promote spermatogenesis (men) and estrogen production (women)

Question 22

What does hCG do?

Answer 22

allows placental growth and increases uterine vascularization.

Question 23

which tissues is thyronine 5’ deiodinase D1 found?

Answer 23

D1 isoform preps T3 for export and is found in liver, kidney and thyroid gland

Question 24

Which tissues is thyronine 5’ deiodinase D2 found?

Answer 24

brain, pituitary, muscle (skeletal and cardiac) is for maintaining intracellular T3 levels

Question 25

What does thyronine 5 deiodinase do?

Answer 25

converts T4 to rT3