Adrenergic Receptors Flashcards
What is the G protein and effectors for alpha1?
Gq
Increase phospholipase C, IP3 and DAG, intracellular Ca
Which receptors have greater than or equal to agonist activity by epinephrine compared to NE?
Alpha 1 and alpha 2
Where are alpha1 receptors found?
Vascular, GU SM, liver, intestinal smooth muscle, heart
What are the responses resulting from alpha1 activation?
Contraction of vascular and GU SM
Glycogenolysis and gluconeogenesis in the liver
Hyperpolarization and relaxation in intestinal SM
Increased contractile force and arrhythmias in the heart
What is the G protein and effectors for Alpha2 receptors?
Gi, Go
Decreased adenylyl cyclase and cAMP
Where are alpha2 receptors found?
Pancreatic islets (beta cells)
Platelets
Nerve terminals
Vascular SM
What are the responses after alpha2 receptor activation?
Decreased insulin secretion from beta islet cells
Platelet aggregation
Decrease release of NE from nerve terminals
Contraction of vascular smooth muscle
Which receptors have Gs as their G protein?
Beta 1-3
Increase adenylyl cyclase, cAMP, L type Ca channel opening
What are the agonists for beta1?
Epi = Ne
Where are beta1 receptors found?
Juxtaglomerular cells and the heart
What are the responses for beta1 activation?
Increased renin secretion by JG cells
Increased force and rate of contraction and AV nodal conduction velocity in the heart
What are the agonists for beta2 receptors?
Epi»_space; NE
Where are beta2 receptors found?
SM (vascular, bronchial, GI, GU)
Skeletal muscle
What are the responses upon beta2 activation?
Relaxation of SM
Glycogenolysis and uptake of K in skeletal muscle
What are the agonists for beta3 receptors?
NE > Epi
