Cell Signaling

Question 1

What is the effect of norepinephrine, epinephrine or isoproterenol on Gs and cAMP production in the heart?

Answer 1

Increased activation of Gs, increased production of cAMP, Ca2+ influx into heart cells

Increased rate of heart contraction

Question 2

What is an antagonist for B1-adrenergic receptor signaling in the heart?

Answer 2

Propanolol and metoprolol

Decrease rate of heart contraction; beta blockers

Question 3

What is the effect of norepinephrine, epinephrine or phenylephrine on Gq and PLC activation in the peripheral vasculature?

Answer 3

IP3 and DAG levels increase, Ca2+ release from the ER, further influx of Ca2+ into cytoplasm

Smooth muscle contraction

Question 4

What is the effect of peripheral vasoconstriction on blood pressure?

Answer 4

Vasoconstriction reduces blood flow to the skin and increases blood pressure

Question 5

What is an antagonist for a1-adrenergic receptor signaling in the peripheral vasculature?

Answer 5

Prazosin

Decrease vasoconstriction, decrease blood pressure

Question 6

What is the effect of muscarine on m2-muscarinic cholinergic receptor signaling by Gi and adenylyl cyclase inhibition in the heart?

Answer 6

Inhibits adenylyl cyclase activation by Gs B1-adrenergic receptor signaling

Decrease rate of heart contraction

Question 7

What proteins degrade cAMP?

Answer 7

Phosphodiesterases (PDE)

Question 8

Give some examples of PDE inhibitors.

Answer 8

Caffeine, theophylline, Milinirone, Rolipram

cGMP specific - Viagra

Question 9

What is the effect of acetylcholine on m2-muscarinic cholinergic receptor signaling by K+ channel activation in the heart?

List an antagonist.

Answer 9

Acetylcholine binding causes the K+ channels to open (BY subunit), membrane hyperpolarization and decreased excitability

Decreased heart rate and contraction

Atropine

Question 10

What is the effect of epinephrine, isoproterenol or albuterol on B2-adrenergic receptor signaling through Gs and cAMP production in the lung?

Answer 10

Activation of adenylyl cyclase and cAMP production, PKA inhibits smooth muscle contraction

Bronchodilation and dilation of vasculature supplying blood to the lungs, heart, and muscle

Question 11

What is the effect of acetylcholine on m3-muscarinic cholinergic receptor signaling through PLC activation in the lung?

List an antagonist.

Answer 11

Activation leads to IP3 and DAG, Ca2+ release from the ER, Ca2+ influx from the extracellular space

Smooth muscle contraction, bronchoconstriction