MAJOR AUTONOMIC RECEPTORS

Question 1

• CNS neurons
• SPN
• some presynaptic sites
• Formation of IP3 and DAG, increased intracellular calcium

Answer 1

Muscarinic M1

Question 2

• Myocardium
• Smooth muscle
• some presynaptic sites
• CNS neurons
• Opening of potassium channels,
• inhibition of adenylyl cyclase

Answer 2

Muscarinic M2

Question 3

• Exocrine glands
  (smooth muscle and endothelium)
• CNS neurons
• Like M1 receptor-ligand binding

Answer 3

Muscarinic M3

Question 4

• CNS neurons; possibly vagal nerve endings
• Like M2 receptor-ligand binding

Answer 4

Muscarinic M4

Question 5

• Vascular endothelium, especially cerebral vessels;
• CNS neurons
• Like M1 receptor-ligand binding

Answer 5

Muscarinic M5

Question 6

• Postganglionic neurons
• some presynaptic cholinergic terminals;
• pentameric receptors typically contain α- and β-type subunits only (see Chapter 7)
• Opening of Na+, K+ channels, depolarization

Answer 6

Nicotinic NN

Question 7

• Skeletal muscle neuromuscular end plates; receptors typically contain two α1- and β1-type subunits in addition to γ and δ subunits
• Opening of Na+, K+ channels, depolarization

Answer 7

Nicotinic NM

Question 8

• Postsynaptic effector cells, especially smooth muscle
• Formation of IP3 and DAG, increased intracellular calcium

Answer 8

Alpha1

Question 9

• Presynaptic adrenergic nerve terminals, platelets, lipocytes, smooth muscle
• Inhibition of adenylyl cyclase, decreased cAMP

Answer 9

Alpha2

Question 10

• Postsynaptic effector cells, especially heart, lipocytes, brain;
• presynaptic adrenergic and cholinergic nerve terminals, juxtaglomerular apparatus of renal tubules, ciliary body epithelium
• Stimulation of adenylyl cyclase, increased cAMP

Answer 10

Beta1

Question 11

• Postsynaptic effector cells, especially smooth muscle and cardiac muscle
• Stimulation of adenylyl cyclase and increased cAMP.
• Activates cardiac Gi under some conditions.

Answer 11

Beta2

Question 12

Postsynaptic effector cells, especially lipocytes; heart
- Stimulation of adenylyl cyclase and increased cAMP1

Answer 12

Beta3

Question 13

• Brain; effector tissues, especially smooth muscle of the renal vascular bed
• Stimulation of adenylyl cyclase and increased cAMP

Answer 13

D1 (DA1), D5

Question 14

• Brain; effector tissues, especially smooth muscle;
• presynaptic nerve terminals
• Inhibition of adenylyl cyclase
• Increased potassium conductance

Answer 14

D2 (DA2)

Question 15

• Brain
• Inhibition of adenylyl cyclase

Answer 15

D3

Question 16

• Brain, cardiovascular system
• Inhibition of adenylyl cyclase

Answer 16

D4