Autonomic & NMJ Pharmacology

Question 1

What are the nicotinic receptors and where are they?

Answer 1

N1 (ganglia)

N2 (NMJ)

Question 2

What are the muscarinic receptors and where are they?

Answer 2

M1 (neronal)

M2 (cacrdiac and presynaptic)

M3 (smooth muscle and glands)

Question 3

What are the alpha receptors?

Answer 3

A1

A2

Question 4

What are the beta receptors?

Answer 4

B1

B2

B3

Question 5

What receptors are ionotropic?

Answer 5

Nicotinic

Question 6

What receptors use G proteins?

Answer 6

All of them apart from nicotinic, which is ionotropic

Question 7

What receptors do most drugs not distinguish between?

Answer 7

Sub classes of:

muscarinic

alpha

beta

Question 8

What is the typical process of synaptic transmission?

Answer 8

1. Synthesis and packaging of neurotransmitter into synsynaptic terminal
2. Na⁺ action potential invades terminal
3. Depolarise and activates voltage gated Ca²⁺ channels
4. Triggers Ca⁺ dependent exocytosis of vesicles of transmitter
5. Transmitter difuses across synaptic cleft and binds to receptor to provide a post synaptic response
6. Presynaptic autoreceptors inhibit further transmitter release
7. Transmiter is inactivated by uptake into glia or neurones
8. Transmitter is metabolised within cells

Question 9

What are potential sites of action for pharmacology of the NMJ?

Answer 9

Inhibit choline transporter

Block voltage gated Ca²⁺ channels

Block vesicle fusion

Non polarising nicotinic receptor blocker

Depolarising nicotinic receptor blocker

Prolong the action potential

Block acetylcholinesterase

Question 10

What are some clinical applications of pharmacolgy at the NMJ?

Answer 10

Non polarising or depolarising blockers used for paralysis during surgery, electroconvulsive therapy or controlling spasms in tetanus

Botulinum toxin used for treating muscle spasms or cosmetic procedures

Anti cholinesterase used for treating myasthenic syndrome, reversing action of non depolarising blocker or countering botulinum poison

Question 11

Where could pharmacology of the ANS be at?

Answer 11

Ganglionic transmission

Post ganglionic sympathetic transmission

Post ganglionic parasympathetic transmission

Question 12

What are potential sites of action for ganglionic transmission?

Answer 12

Inhibit choline transporter

Block voltage gated Ca²⁺ channels

Block vesicle fusion

Block aceylcholine activated channel

Non depolarising nicotinic receptor blockers

Deploarising nicotinic receptor blocker

Activate nicotinic receptors

Question 13

What are potential clinical applicaitons of pharmacology of ganglionic transmission?

Answer 13

Almost none because the drugs affect both the sympathetic and parasympathetic, and possible th NMJ so there are so many side effects

Question 14

What are post ganglionic parasympathetic transmission potential sites of action?

Answer 14

Muscarinic receptor antagonist

Muscarinic receptor agonist

Question 15

What are clinical applicaitons of post ganglionic parasympathetic pharmacology?

Answer 15

Agonist mimics the effects of the parasympathetic system

Antagonist blocks the effects of the parasympathetic system

Question 16

What are post ganglionic sympathetic transmission potential sites of aciton?

Answer 16

Block the enzyme that produces neurotransmitter

Block the transporter that filles the vesicle with noradrenaline

Introduce a false transmitter

Activate inhibitory presynaptic autoreception

Block A or B postsynaptic receptors

Stimulate noradrenaline release

Inhibit uptake into neurons

Activate postsynaptic receptors

Question 17

What can the inhibition of dopa decarboxylase do?

Answer 17

Stop the synthesis of noradrenaline

Question 19

What are clinical applications of pharmacology of postganglionic sympathetic transmission?

Answer 19

A1 agonist used as decongestant and to dilate pupil

A2 agonist used in the treatment of hypertension

B2 agonist used in the treatment of asthma

B1 antagonist used in the treatment of hyper tension