Pharm: Cholinomimetics

Question 1

Cholinomimetics mimic ____________; they are also called parasympathomimetics.

Answer 1

acetylcholine (“enjoy an acetyl-Cola”)

Question 2

What are the two subtypes of cholinergic receptors?

Answer 2

1. muscarinic

2. nicotinic

Question 3

Where are nicotinic receptors found?

Answer 3

1. autonomic ganglia (think of the electric wire transfomers- where pre-ganglionic synpase on poster ganglionic)
2. skeletal neuromuscular junctions (think of the outlet- skeletal muscle motor end plate)
3. adrenal gland- directly (think of the adrenal beanie)

Question 4

Where are muscarinic receptors found?

Answer 4

autonomic effector tissues (smooth muscle of heart and glands) NOT ganglia

Question 5

What is the transmembrane signaling mechanism for nicotinic receptors?

Answer 5

Nicotinic receptors are ion channels that allow positive ion flow

Question 6

What is the signaling mechanism for muscarinic receptors?

Answer 6

G proteins

Question 7

M1, M2, and M3 are coupled to which G proteins?

Answer 7

M1 = Gq
M2 = Gi
M3 = Gq 

(Think of the QIQ Mart in front of the M1, M2, M3 motorcycles)

Question 8

The Gq receptors couple to the _________ pathway.

Answer 8

IP3-DAG (think of the three dogs on the M1 and M3 motorcycles)

Question 9

Gi protein activation causes a DECREASE in __________ molecules.

Answer 9

cAMP (think of the packed up cAMP tent on the M2 motocycle)

Question 10

Where are M1 receptors found?

Answer 10

CNS and GI enteric nervous system

Question 11

Where do M2 receptors affect the heart?

Answer 11

The atria- specifically through slowing down conduction in the SA and AV nodes (think of the girl with the lower part of her jacket torn off)

Question 12

Where do M3 receptors exist?

Answer 12

glands (think of the glandular sponge), smooth muscle (think of the smooth muscle paint job on the motorcycle)

Question 13

Why does M3 activation lead to vasodilation?

Answer 13

Because the receptor activates NO release; without this- such as in the case of endothelial cell damage) muscarinic agonists do lead to vasoconstriction (think of the dilated exhaust pipe on the M3 motorcycle)

Question 14

In what circumstances do you administer bethanecol?

Answer 14

For non-obstructive bowel and bladder disorders- such as post-op ileus, megacolon, or neurogenic bladder (think of the Beth the construction working pour cement from a colon-like tube next to the “Do Not Obstruct” sign

Question 15

What is the main use of pilocarpine?

Answer 15

stimulate salivary glands to treat dry mouth- such as Sjogren’s or radiation damage (think of the PILe-O-CARP with open, dripping mouths) and reduce IOP for glaucoma

Question 16

Muscarinic agonists ________ intraocular pressure.

Answer 16

reduce by contracting the ciliary body making the lens more spherical and accomodated (think of the round lens-like buoys on the net)

Question 17

Pilocarpine _________ the pupil.

Answer 17

Constricts- useful in acute angle-closure glaucoma (think of the constricted fisherman’s hood)

Question 18

What is carbachol used to treat?

Answer 18

Glaucoma- pupillary constriction (think of the carbon-fearing constricted hood tenant)

Question 19

What cholinergic receptors does carbachol stimulate?

Answer 19

Both nicotinic and muscarinic- think of the guy inhaling the cigarette smoke from below while looking at the motorcyles

Question 20

In addition to aggravating asthma and COPD (by contracting bronchial smooth muscle), what disorder can cholinomimetic aggravate?

Answer 20

Peptic ulcer disease (think of methacholine)

Question 21

What is methacholine used for?

Answer 21

Instigating asthma for pulmonary testing (think of the marathoner)

Question 22

What is a partial agonist at nicotinic receptors used to treat smoking addiction?

Answer 22

Varenicline aka Chantix (think of the smoking cessation poster 1-800-VERY-CLEAN)