Receptors in the Heart and Blood Vessels

What receptor(s) in the PNS act on blood vessels?

M3

What G-Protein does M3 couple to?

Gq

What does Gq do?

stimulates PLC, cleaves PIP2 to DAG, activates PKC, IP3 binds and opens Ca channels, ER release Ca

What does M3 do in the blood vessels?

cause vasodilation

How does M3 cause vasodilation?

by stimulating nitric oxide (NO) formulation and release

What does nitric oxide do in the blood vessels?

it is a vasodilator (relaxation)

What receptor(s) in the PNS act on the heart?

M2

What G-Protein does M2 couple to?

Gi

What does Gi do?

inhibits adenyly cyclase, decreases cAMP, decreases PKA activation

What does M2 do in the heart?

slows heart rate

What receptor(s) in the SNS act on blood vessels?

A1 and B2 (more A1 than B2)

What does A1 do in the blood vessels?

causes vasoconstriction/smooth muscle contraction

What does B2 do in the blood vessels?

causes vasodilation/smooth muscle relaxation

What receptor(s) in the SNS act on the heart?

B1 and B2

What do beta receptors couple to?

Gs

What does Gs do?

stimulates adenylyl cyclase, increases cAMP, activates PKA

What does B1 do in the heart?

increases heart rate and force of contraction

What does B2 do in the heart?

opens the aorta for contraction