L 30 Intro to Endocrinology

Question 1

Describe the Prolactin signaling in the pituitary

Answer 1

Pituitary is signaled by dopamine and TRH in regards to prolactin production Dopamine decreases release TRH increases release

Question 2

Bromocriptine (Parlodel) and Cabergoline

Answer 2

Suppress prolactin secreting tumors through dopamine agonism Cabergoline more effective and better tolerated Don’t use with pregnancy

Question 3

Describe the GH axis in the pituitary

Answer 3

GHRH signals release

Somatostatin inhibits release

GH = somatotropin

IGF-1 mediates effects

Increases gluconeogenesis in the liver, but decreases glucose use in the periphery–favors fat use for energy

Question 4

Somatotropin

Somatotrem (Protropin)

Answer 4

GH Agonists

Used in growth failure due to GH deficiency, renal disease, Turner’s syndrome

Cause fluid retention and edema causing papilledema and intracranial pressure

Hyperglycemia, hypothyroidism

Don’t use in DM or hypothyroidism patients

Question 5

Sermorelin (Geref)

Answer 5

GH agonist

Synthetic GHRH

Not as effective as GH therapy

Used diagnostically

Question 6

Mecasermin (Increnex)

Mecasermin rinfabate (Iplex)

Answer 6

Recombinant IGF-1

Not as effective as GH therapy

Used in cases where GH is no longer effective like GH receptor deletion or GH antibodies present, or when IGF-1 genes are deleted or mutated

Question 7

Octreotide (Sandostatin)

Lanreotide (Somatuline)

Answer 7

Somatostatin agonists

Inhibits the secretion of pituitary and GI hormones

Treats GH excess–acromegaly

Also treats other hormone secreting tumors–can reduce tumor size/growth

Treats excessive diarrhea

Can cause gall stones

Question 8

Pegvisomant (Somavert)

Answer 8

GH receptor antagonist

Used in GH excess syndromes–acromegaly

Returns IGF-1 levels to normal

May cause a GH secreting tumor from lack of feedback to the pituitary