Wk1 Pituitary Phys

Question 1

Where does prolactin originate?

Answer 1

anterior pituitary

Question 2

What inhibits prolactin release?

Answer 2

dopamine (primary)

GHIH – somatostatin

Question 3

Location of GHRH release?

Answer 3

hypothalamus

Question 4

Location of GHIH (somatostatin) release?

Answer 4

hypothalamus

Question 5

somatostatin receptor type:

Answer 5

Gi-coupled –> decreases cAMP, activates K+ channels

Question 6

GHRH receptor type in anterior pituitary?

Answer 6

Gs –> increases cAMP

Question 7

another name for GH:

Answer 7

somatotropin

Question 8

Indicator for tissue levels of GH receptors:

Answer 8

GHBP (growth hormone binding protein)

Question 9

GH receptor mechanism in tissues:

Answer 9

Tyrosine kinase –> JAK/STAT

**slide 7

Question 10

GH stimulates liver to produce?

Answer 10

IGF-1 (insulin like growth factor 1)

-very similar to insulin

Question 11

Opposing effects of GH and IGF-1:

Answer 11

GH:

• decreased insulin sensitivity
• lipolysis

IGF-1:

• insulin-like activity
• anti-lipolytic activity

Question 12

Similar effects of GH and IGF-1:

Answer 12

protein synthesis

epiphysial growth

Question 13

when is IGF-1 more important than GH?

Answer 13

stimulating chondrogenesis at epiphysial growth plate in kids

Question 14

Negative feedback inhibition on…

Answer 14

slide 13

Question 15

GHRH pharmaceutical analog:

Answer 15

Sermorelin

Question 16

HGH analog drug:

Answer 16

Somatotropin

Question 17

IGF-1 drug analog:

Answer 17

Mecasermin

**used in children who can’t respond to GH for stimulation of growth

Question 18

Hypersecretion of GH in adults leads to?

Answer 18

acromegaly

**think Andre the Giant

Question 19

Targets for treatment of GH hypersecretion:

Answer 19

somatostatin receptors

dopamine receptors

Question 20

What kind fo receptor is D2?

Answer 20

Gi(alpha) –> decreases cAMP

Question 21

Dopamine agonist used to treat GH hypersecretion:

Answer 21

Bromocriptine

Question 22

long acting somatostatin analog:

Answer 22

Octreotide

Question 23

GH receptor antagonist:

Answer 23

Pegvisomant

Question 24

What is likely to happen to GHRH and GH if given Pegvisomant (a GH receptor antagonist)?

Answer 24

increased due to reduced IGF-1 and subsequent lack of feedback inhibition

Question 25

Prolactin receptor type?

Answer 25

Tyrosine kinase --> JAK/STAT

Question 26

Prolactin's physiological effects:

Answer 26

Breast development during pregnancy milk production

Question 27

Why does prolactin increase if pituitary stalk is severed?

Answer 27

tonic inhibition by dopamine is removed

Question 28

Is there negative feedback with increasing prolactin levels?

Answer 28

NO

Question 29

Two dopamine agonist used to inhibit prolactin secretion:

Answer 29

Cabergoline Bromocriptine

Question 30

Why are dopamine agonists effective in treating prolactin secreting pituitary tumors?

Answer 30

they express high level of D2 receptors