Chapter 10: Cholinergic Drug Classes & Receptor Overview

Question 1

Function of Hemicholinium-3

Answer 1

• ACh synthesis inhibitors
• Blocks the high affinity transporter for choline into the neuron
• Can’t get choline (precursor) into neuron
• Can’t make ACh

Question 2

Function of Vesamicol

Answer 2

• ACh storage inhibitors
• Blocks ACh-H+ anti-porter preventing the storage of ACh
• Reduces the normal amount of ACh that gets released into the synpase
• Drugs of this class have similiar phsiological effects but non-specific for all neurons regardless of receptor

Question 3

Function of Botulinum Toxin A (Clostridium Botulinum)

Answer 3

• ACh release inhibitors
• Degrades SNAP-25
• ->A protein in the Snare complex that is required for vescile fusion/zipping to the membrane
• ->Prevents ACh release into the synapse
• ->When injected, it induces paralysis of muscle because blocks any synaptic release at the site

Question 4

What are the two receptors that ACh can bind to?

Answer 4

• Muscarinic-G protein Coupled

- Nicotinic-Ligand gated ion channel

Question 5

Acetylcholinesterase inhibitors: how they work

Answer 5

• Work by targeting the enzyme responsible for the degradation of ACh
• Indirectly acting ACh receptor agonist

Question 6

Where can i find muscarinic (mAChR) receptors?

Answer 6

• Terminal synpases of all parasympathetic postgangloinic fibers (cardiac, smooth, muscle)
• Sympathetic postganglionic fibers (Sweat glands)
• CNS

Question 7

Where can I find Nicotinic (nAChR) receptors?

Answer 7

• Postsynaptically at many excitary autonomic synapses
• CNS (in the brain and various neurons)
• NMJ (somatic, skeletal muscle)