Peripheral Nervous System Pharmacology

Question 1

Muscarinic receptors

Answer 1

-cholinergic-ACh
-G-protein coupled; 5 subtypes
On:
-autonomic ganglia-depolarize postsynaptic neurons
-Heart-decrease HR, conduction velocity, and contractility
-Smooth muscle (eye, bronchioles, GI, UG)-contraction
-Secretory glands-increase secretion (tears, bronchial mucous, GI, eccrine sweat, etc)
-Vascular endothelium-dilate blood vessels
-GI sphincters- relaxation

Question 2

Nicotinic receptors

Answer 2

-cholinergic-ACh
-ligand gated ion channels; 2 subtypes
On:
-neuromuscular junction-skeletal muscle contraction
-Autonomic ganglia-depolarize postsynaptic neurons
-Adrenal medulla-depolarize medullary cells-> secrete catecholamines

Question 3

alpha-1 receptors

Answer 3

-adrenergic-NE and E
-Gq-protein coupled
On:
-smooth muscle (eye, vascular, UG, hair follicles, sphincters)-contraction (penis->ejaculation)
-Liver- stimulate glycogenolysis, gluconeogenesis
-Intestine- relax (decrease motility)
-Secretions-stimulate apocrine sweat glands (axilla and pubic); viscous salivary secretions

Question 4

alpha-2 receptors

Answer 4

-adrenergic-NE and E
-Gi and Gq protein coupled
On:
-Axon terminals (autoreceptors)-decrease NE release
-Pancreatic B cells- decrease insulin release
-vascular smooth muscle-contraction
-platelets- aggregation

Question 5

Cholinergic neurons

Answer 5

-release ACh
Found:
-all motor (somatic) neurons
-all preganglionic ANS neurons (1st synapse always cholinergic)
-all postgang parasympathetic
-some postgang sympathetic-most sweat glands, some blood vessels in skeletal muscle

Question 6

Adrenergic neurons

Answer 6

• release norepinephrine (NE), epinephrine (E), or dopamine (DA)
• most postgang symp release NE
• Adrenal medulla releases E and NE

Question 7

Beta-1 receptors

Answer 7

-adrenergic-NE and E
-Gs protein coupled
On:
-heart-increase HR, conduction velocity, contractility
-kidney (JG cells)- increase renin release

Question 8

Beta-2 receptors

Answer 8

-adrenergic- NE and E
-Gs protein coupled
On:
-Smooth muscle (eye, bronchioles, GI, UG, vascular)- relax
-Heart-increase HR, contractility
-Liver and skeletal muscle- increase glycogenolysis, gluconeogenesis
-Pancreatic B cells- increase insulin release
-Bronchial glands- watery secretion
-GI-decrease acid secretion, increase amylase secretion

Question 9

Beta-3 receptors

Answer 9

-adrenergic- NE and E
-Gs protein coupled
On:
-lipcytes-activates lipolysis

Question 10

Dopamine receptors

Answer 10

-adrenergic
On:
-vascular smooth muscle (esp renal vasculature)-dilate blood vessels (Gs)
-axon terminals (autoreceptors)- decrease DA release (Gi)
-Cholinergic neurons in gut-decrease GI motility (Gi)