G-Protein Linked 2nd Messengers

Question 1

What are the major functions of alpha-1, and what is it’s G-protein class?

Answer 1

Increase smooth muscle contraction, increase pupillary dilator muscle contraction (mydriasis), increase intestinal and bladder sphincter muscle contraction.

Protein class: q

Question 2

What are the major functions of alpha-2, and what is it’s G-protein class?

Answer 2

Decrease sympathetic (adrenergic outflow), decrease insulin release, decrease lipolysis, decrease aqueous humor production, and increase platelet aggregation.

G-protein: i

Question 3

What are the major functions of beta-1, and what is it’s G-protein class?

Answer 3

Increases: heart rate, contractility (one heart), renin release, and lipolysis.

G-protein: s

Question 4

What are the major functions of beta-2, and what is it’s G-protein class?

Answer 4

Vasodilation, bronchodilation (two lungs), increases: lipolysis, insulin release, glycogenolysis, aqueous humor production, celular K+ intake, and decrease uterine tone contractions.

G-protein: s

Question 5

What are the major functions of beta-3, and what is it’s G-protein class?

Answer 5

Increases: lipolysis, thermogenesis in skeletal muscle, increase bladder relaxation.

G-protein: s

Question 6

What are the major functions of miu-1, and what is it’s G-protein class?

Answer 6

Mediates higher cognitive function, stimulates enteric nervous system.

G-protein: q

Question 7

What are the major functions of miu-2, and what is it’s G-protein class?

Answer 7

Decreases: heart rate and contractility of atria

G-protein: i

Question 8

What are the major functions of miu-3, and what is it’s G-protein class?

Answer 8

Increase: exocrine gland secretion (lacrimal, sweat, salivary, gastric acid), gut peristalsis, bladder contraction, bronchoconstriction, pupillary sphincter muscle contraction (miosis), ciliary muscle contraction (accommodation), insulin release.

G-protein: q

Question 9

What are the major functions of delta-1, and what is it’s G-protein class?

Answer 9

Relaxes renal vascular smooth muscle, activated direct pathway of striatum.

G-protein: s

Question 10

What are the major functions of delta-2, and what is it’s G-protein class?

Answer 10

Modulates transmitter release especially in brain, inhibits indirect pathway of striatum.

G-protein: i

Question 11

What are the major functions of histamine-1, and what is it’s G-protein class?

Answer 11

Increases: nasal and bronchial mucus production, vascular permeability, bronchoconstriction pruritus, pain

G-protein: q

Question 12

What are the major functions of histamine-2, and what is it’s G-protein class?

Answer 12

Increases gastric acid secretion

Question 13

What are the major functions of vasopressin-1, and what is it’s G-protein class?

Answer 13

Increases vascular smooth muscle contraction

G-protein: q

Question 14

What are the major functions of vasopressin-2, and what is it’s G-protein class?

Answer 14

Increases water permeability and resorption via upregulating aquaporin-2 in collecting tubules (twobules) of kidney

G-protein: s

Question 15

By which mechanism does NE cause vasoconstriction?

Answer 15

NE binds alpha-1 receptors to activate Gq, which increases cytosolic calcium in smooth muscle, in turn causing vasoconstriction.