Cholinergic agonists

Question 1

Synth of ACh

Answer 1

AcetylCoA +Choline = ACh; by choline acetyltransferase

Question 2

Degr of ACh

Answer 2

ACh = choline + acetate; by acetylcholinesterase

Question 3

ACh Rs are M, N or both?

Answer 3

Both

Question 4

What kind of Rs are nAChRs and where are they?

Answer 4

Ligand-gated ion channels located in muscle, autonomic ganglia, adrenal chromaffin cells and brain

Question 5

what kind of Rs are mAChRs?

Answer 5

GTP-binding protein-linked receptors

Question 6

Where are M2 Rs and what do they do?

Answer 6

Found primarily in cardiac tissue and cause hyperpolarization through increased potassium conductance

Question 7

Where are M3 Rs and what do they do?

Answer 7

Predominantly in smooth muscle and secretory glands and cause PI turnover and increased calcium influx

Question 8

Ganglion N Rs are selectively blocked by ______

Answer 8

hexamethonium

Question 9

Muscle N Rs are selectively blocked by ______

Answer 9

curare

Question 10

GI effects of ACh

Answer 10

Increased tone (motility); relaxation at sphincters

Question 11

Cardiac effects of ACh

Answer 11

Bradychardia and decreased conduction

Question 12

Muscarine

Answer 12

Contained in some mushrooms (Inocybe and Clitocybe); ingestion causes muscarine poisoning

Question 13

Which drug can reverse muscarine poisoning?

Answer 13

atropine

Question 14

Methacholine

Answer 14

• AChE resistant
• may be used for bronchial hyper-reactivity test VERY carefully
• primarily muscarinic

Question 15

Bethanechol

Answer 15

• bladder mAChRs
• used post-op
• prevent salivation
• BBB

Question 16

Carbachol

Answer 16

-used in wide-angle glaucoma (last line)

Question 17

Pilocarpine

Answer 17

• partial agonist
• miotic agent for glaucoma
• promotes salivation
• CNS

Question 18

direct cholinomimetic

Answer 18

agonist

Question 19

indirect cholinomimetic

Answer 19

AChE antag

Question 20

contraindications

Answer 20

• asthma – may precipitate an attack due to M mediated bonchoconstriction
• urinary obstruction
• acid peptic disease – may induce gastric acid secretion

Question 21

classes of cholinergic agonists

Answer 21

choline esters & muscarinics

Question 22

Nicotine

Answer 22

-initially activates ganglion AChRs, which is then followed by R blockage resulting from persistent depolarization

Question 23

Nicotine poisoning can cause ___

Answer 23

tachycardia or bradycardia, hypertension or hypotension, depending on the dose and timing.

Question 24

Clinical uses of nicotine

Answer 24

not used clinically except nicotine patches to aid in the cessation of smoking