Pharm of NMJ

Question 1

ACh synthesis

Answer 1

choline transporter brings choline into cell

choline + acetyl CoA – choline acetyltransferase (ChAT) –> ACh

Question 2

ACh storage

Answer 2

ACh vesicular transporter uses ATP to shuttle ACh to storage vesicles that can each hold 1K-50K molecules of ACh

Question 3

How many ACh storage vesicles may a motor nerve terminal contain?

Answer 3

> 300K

Question 4

Vesamicol

Answer 4

blocks ACh vesicular transporter

Question 5

What causes voltage gated Ca2+ channels to open?

Answer 5

depolarization

Question 6

What does Ca2+ do in the presynaptic cell?

Answer 6

promote ACh vesicle membrane fusion

Question 7

VAMP and SNAP

Answer 7

vescicular and plasma membrane proteins that initiate fusion of vesicle to membrane to release ACh

Question 8

AChE

Answer 8

breaks down ACh to choline and acetate

Question 9

nAChR

Answer 9

ligand gated ion channel activated by ACh and nicotine post junctionally and prejunctionally at NMJ

Question 10

tetrodotoxin

Answer 10

puffer fish poison

MOA: inhibition of voltage gated Na+ channels block axonal conduction

Question 11

What are these symptoms of? weakness, dizziness, paresthesias of face and extremities, loss of reflexes, hypotension, generalized paralysis, and death due to respiratory failure and hypotension

Answer 11

tetrodotoxin

Question 12

local anesthetics

Answer 12

inhibit voltage gated Na+ channels inhibiting axonal conduction

Question 13

What are local anesthetics used for?

Answer 13

pain control during procedures

Question 14

lidocaine, bupivacaine, and procaine are examples of what?

Answer 14

local anesthetics

Question 15

botulinum toxin

Answer 15

caused by clostridium botulinum, gram + rod shaped, spore forming anaerobic bacteria
found on vegetables, fruits, and seafood and in soil

Question 16

botulinum toxin MOA

Answer 16

cleaves components of core SNARE complex involved in exocytosis preventing release of ACh

Question 17

symptoms of botulism

Answer 17

acute onset of bilateral cranial neuropthies with symmetric descending weakness
blurred vision
nausea, vomiting, abdominal pain, diarrhea, and dry mouth

Question 18

What is botulinum toxin used for clinically?

Answer 18

improvement in appearance of lines/wrinkles of the face, prophylaxis of chronic migraine HA

Question 19

tetanus toxin

Answer 19

NS disorder characterized by muscle spasms that is caused by toxin-producing anaerobe clostridium tetani found in soil

Question 20

tetanus toxin MOA

Answer 20

blocks fusion of synaptic vesicles by targeting synaptobrevin

Question 21

What toxin is retroactively transported to the spinal cord?

Answer 21

tetanus toxin

Question 22

Symptoms of tetanus

Answer 22

spastic paralysis, trismus, autonomic overactivity (restlessness, sweating, tachycardia), stiff neck, board-like rigid abdomen, opisthotonus, dysphagia

Question 23

agonists

Answer 23

activate the receptor to signal as a direct result of binding to it

Question 24

antagonists

Answer 24

bind to receptors but do not activate generation of a signal

Question 25

curare alkaloids - d-tubocurarine

Answer 25

antagonist
competes with ACh for the nAChR on the motor end plate, decreasing the size of the EPP
causes flacid paralysis
used during anesthesia to relax skeletal muscle
reversed with AChE inhibitor

Question 26

succinylcholine

Answer 26

agonist
depolarizing neuromuscular blocker that binds to skeletal muscle and causes depolarization; continued depolarization leads to receptor blockade and paralysis
used as induction for anesthesia
reversed by time