Hypothal and Pit (Growth Hormone)

Question 1

Which two anterior pituitary hormones activate JAK/STAT receptors? What receptors do all the other ant pit hormones act on?

Answer 1

GH and prolactin (also DA but not ant. pit.)

others activate G-coupled receptors

Question 2

Which pituitary hormone leads to the release of IGF-1 at its target tissue?

Answer 2

GH

Question 3

How are the JAK/STAT receptors activated?

Answer 3

requires binding of two molecules (1 to two different receptors) which leads to receptor dimerization

Question 4

Which pituitary hormone is important in the regulation of blood glucose due to its anti-insulin actions? If it is missing, how is blood glucose affected?

Answer 4

GH

lack of GH means you lose inhibition of insulin so you get hypoglycemia

Question 5

two recombinant GH drugs are somatropin and somatrem. How are they different?

Answer 5

Somatropin: recombinant GH (identical to human hormone)
Somatrem: GH analog (modified to inc bioavailability etc)

Question 6

How are most pituitary/hypopit replacement hormones given? why?

Answer 6

subcutaneously - cant give proteins orally, they get degraded in stomach

Question 7

What drug can be given to improve wasting in HIV patients?

Answer 7

Somatropin (recombinant GH)

Question 8

Intracranial HTN, otitis media, hypothyroidism, and scoliosis are important adverse effects of what hypothal/pit hormone? how do you get hypothyroidism?

Answer 8

Somatropin - hypothyroidism caused by negative feedback on other pit hormonesthese are AE in children!

Question 9

which hypothal/pit hormone can cause peripheral edema, myalgias, carpal tunnel, and proliferative retinopathy? this drug is contraindicated in what patients?

Answer 9

Somatropin (recombinant GH)

Contraindicated in patients with a known maligancy (WONT cause primary tumor, but can cause existing ones to grow)

Question 10

Which drug can be used in growth hormone deficiency, has few adverse effects, and is less expensive than somatropin? why is it also less effective than somatropin?

Answer 10

Sermorelin - GHRH - wont work if the defect is in the anterior pituitary

Question 11

Some kids with delayed growth have neutralizing antibodies to GH. What can be given to help these kids? what is an important side effect and how should it be given?

Answer 11

Mecasermin - IGF-1 analog
because it has some effect on insulin receptors, it can cause hypoglycemia so it needs to be given 20 min before or after a meal

Question 12

What are two rare side effects of mecasermin and which is more important to watch out for?

Answer 12

Intracranial HTN - can be fatal!
elevation of liver enzymes - asymptomatic
Mecasermin - IGF-1 analog (GH)

Question 13

what cells in the pituitary are responsible for causing acromegaly in adults or gigantism in kids?

Answer 13

somatotrophs - secrete GH

Question 14

Which drug can be used in acromegaly/gigantism because it blocks the GH receptor?

Answer 14

Pegvisomant

Question 15

somatostatin inhibits the release of what 4 substances?

Answer 15

GH Glucagon Insulin Gastrin

Question 16

what drug can be given to reduce symptoms caused by hormone-secreting tumors? what kind of drug is it?

Answer 16

octreotide - somatostatin analog

acromegaly, carcinoid syndrome, gastrinoma, diabetic diarrhea etc

Question 17

what drug can be given to control acute bleeding from esophageal varices?

Answer 17

octreotide - somatostatin analog

Question 18

which hypothal/pit drug can cause nausea, vomiting, flatulence, gallstones, sinus bradycardia and vit B12 deficiency?

Answer 18

octreotide - somatostatin analog

Question 19

what two drugs can be used to treat prolactinomas? what type of drugs are they? which has more adverse effects? why do they work?

Answer 19

Dopamine agonists: Bromocriptine (way more AEs) and Cabergoline
Most prolactinomas retain their ability to be inhibited by dopamine

Question 20

chonic high-dose therapy of what hypothal/pit drugs leads to cold-induced peripheral digital vasospasm and pulmonary infiltrates?

Answer 20

Dopamine agonists: Bromocriptine (way more AEs) and Cabergoline