dopamine, histamine, and vasopressin receptors

Question 1

What do D1 receptors do? G protein class?

Answer 1

s class; relax renal vascular smooth muscle

Question 2

What do D2 receptors do? g protein class?

Answer 2

i class. modulate transmitter release, esp. in brain.

Question 3

What do H1 receptors do? g protein class?

Answer 3

q class. incr. nasal and bronchial mucus production, incr. vascular permeability, contraction of bronchioles, pruritis, and pain.

Question 4

What do H2 receptors do? g protein class?

Answer 4

s class. the promote gastric acid secretion

Question 5

What do V1 receptors do? class?

Answer 5

remember these are vasopressin receptors
they promote vascular smooth muscle contraction
q class

Question 6

What do V2 receptors do? Class?

Answer 6

s class. incr. H2O permeability and reabsorption i nthe collecting tubules of the kidney (V2 in the 2 kidneys)

Question 7

Gq second messangers:

Answer 7

receptor –> phospholipase C. Phosphoplipase C converts PIP2 to IP3 and DAG. DAG activates protein kinase C. IP3 increases intracellular calcium and casues smooth muscle contraction.

Question 8

Gs receptor second messangers

Answer 8

Gs incr. adenylyl cyclise –> incr. cAMP –> incr. protein kinase A. protein kinase A increases Ca concentration in the heart. In smooth muscle, this will block myosin light chain kinase. blocking myosin light chain kinase relaxes smooth muscle. try drawing.
(receptors B1, B2, D1, H2, V2)

Question 9

Gi receptor second messangers

Answer 9

Gi is an INHIBITOR. it blocks adenylyl cyclase, decr. cAMP, decr. protein kinase A, and decr. Ca/ disinhibits myosin light chain kinase. this will cause decr. Ca in the heart. In smooth muscle, it will disinhibit myosin light chain kinase, causing smooth muscle contraction. (receptors M2, alpha 2, D2)