Exam 2 - More Signaling

Question 1

What is somatotropin?

Answer 1

Growth hormone

Question 2

Where is somatotropin produced?

Answer 2

Anterior pituitary

Question 3

Through what does somatotropin act?

Answer 3

Via growth hormone receptor

Question 4

Where is IGF-1 made?

Answer 4

Liver

Question 5

What 4 things does somatotropin affect growth of?

Answer 5

1. Liver
2. Bone
3. Adipose tissue
4. Skeletal muscle

Question 6

How is GH used in children?

Answer 6

Supplemented for GH deficiency

Question 7

How do body builders use GH?

Answer 7

To decrease body fat

Question 8

How is GH used in aging populations?

Answer 8

To decrease loss of muscle mass

Question 9

What is the IC structure of the GH receptor?

Answer 9

Dimer

Question 10

What pathway does GH utilize?

Answer 10

MAPK and Jak/STAT

Question 11

What is the end result of GH using the MAPK pathway?

Answer 11

Cell division/chondrocytes and bone growth during childhood

Question 12

What is the end result of GH using the Jak/STAT pathway?

Answer 12

IGF-1 production in the liver and growth of liver and other tissues

Question 13

What are the levels of IGF-1 in Great Danes vs. Chihuahuas?

Answer 13

High in Danes, Low in Chihuahuas

Question 14

What is special about IGF-1 haplotypes in small breeds?

Answer 14

Impact IGF-1’s signal for production of GH; less GH is made than in larger breeds

Question 15

What occurs in mouse models with elevated GH levels?

Answer 15

Gigantism

Question 16

What occurs in mouse models with GH insensitivity?

Answer 16

Liver is unable to read signal to GH receptor.

Question 17

What type of mutation does the Ames dwarf mouse have that leads to it being GH-deficient?

Answer 17

Loss-of-function

- Pituitary TF mutant

Question 18

When GH signaling decreases, what happens to lifespan?

Answer 18

Increases

Question 19

What does IGF-1 promote survival of when related to bovine somatotropin?

Answer 19

Mammary alveolar cells

Question 20

What 3 things does recombinant BST do?

Answer 20

1. Increases IGF-1 production in liver
2. Increases survival of mammary alveoli
3. Increases production over course of lactation

Question 21

What are the side effects of rBST?

Answer 21

Can cause increased mastitis in cows and pregnancy issues if the cow gets pregnant another time

Question 22

What makes cAMP?

Answer 22

Adenylyl cyclase

Question 23

What does cAMP activate?

Answer 23

PKA

Question 24

What does PKA do?

Answer 24

Phosphorylates and activates many proteins

Question 25

What is cAMP hydrolyzed to?

Answer 25

AMP

Question 26

What facilitates ATP --> cAMP?

Answer 26

Adenylyl cyclase

Question 27

What facilitates cAMP --> AMP?

Answer 27

cAMP phosphodiesterase (PDE)

Question 28

How is PKA activated?

Answer 28

cAMP binds to PKA regulatory subunits, catalytic subunits become active

Question 29

What does adrenaline stimulate in the muscle?

Answer 29

Glycogen breakdown

Question 30

What does glucagon stimulate in the liver?

Answer 30

Glycogen breakdown

Question 31

What stimulates the muscle to break down glycogen?

Answer 31

adrenaline

Question 32

What stimulates the liver to break down glycogen?

Answer 32

glucagon

Question 33

What stimulates the heart to increase HR and force of contraction?

Answer 33

adrenaline

Question 34

What does adrenaline stimulate in the heart?

Answer 34

Increased HR and force of contraction

Question 35

What releases cholera toxin?

Answer 35

Vibrio cholerae

Question 36

What does CTX catalyze in the cell?

Answer 36

Covalent modification of G protein

Question 37

How does CTX act to increase the concentration of cAMP in the cell?

Answer 37

Activates adenylyl cyclase

Question 38

What do elevated cAMP and PKA levels open in the cell in response to CTX?

Answer 38

Chloride (CFTR) channel

Question 39

What ultimately causes watery diarrhea in someone with cholera?

Answer 39

Loss of Cl- and water from the cell

Question 40

What is the therapeutic approach for cholera?

Answer 40

Enkephalin (opioid)

Question 41

Where is adrenaline/epinephrine produced?

Answer 41

Adrenal medulla

Question 42

Where does adrenaline bind?

Answer 42

GPCRs (adrenergic receptors)

Question 43

What does adrenaline lead to in the alpha-1 pathway?

Answer 43

Vasoconstriction of GI and periphery blood vessels

Question 44

What does adrenaline lead to in the alpha-2 pathway?

Answer 44

GI sphincter innervation and constriction

Question 45

What happens to adenylyl cyclase, cAMP, and smooth muscle in the alpha-2 adrenaline pathway?

Answer 45

Adenylyl cyclase activates cAMP increases Smooth muscle contracts

Question 46

What happens to adenylyl cyclase, cAMP, and smooth muscle in the beta adrenaline pathway?

Answer 46

Adenylyl cyclase activates cAMP increases Smooth muscle relaxes

Question 47

What does adrenaline lead to in the beta pathway?

Answer 47

Increased HR, open airways (heart and bronchioles)

Question 48

What is special about the way caffeine enters a cell?

Answer 48

It is lipid and water soluble so can enter the cell without binding to a receptor

Question 49

Caffeine is a neuro_____.

Answer 49

stimulant

Question 50

What does caffeine inhibit and what results?

Answer 50

Inhibits PDE, resulting in increased cAMP concentration, increased PKA activity (increased HR)

Question 51

What are 2 ways to increase [cAMP]?

Answer 51

1. Activate adenylyl cyclases (GPCR activation) | 2. Inhibit PDE