9-Cholinergic Pathway Flashcards
Why are cholinergic and anticholinergic drugs limited?
They’re limited by the ubiquitous and complicated nature of cholinergic pathways- it’s hard to achieve desired therapeutic effects without adverse effects.
What is the enzyme that combines Acetyl-CoA and Choline to form Ach?
CAT (choline acetyltransferase)
What is the transporter that brings the choline molecule into the cytoplasm?
NCS (Na-Choline symporter)
What drug blocks the NCS transporter?
Hemicholinium
After Ach is synthesized, where is it stored?
Vesicles
What is the transporter that brings the Ach into the vesicle?
ATPase antiporter (takes H out)
What drug blocks the ATPase antiporter on the vesicle, thus not allowing Ach to enter vesicles to be released?
Vesamicol
An increase in what ion causes the vesicles with Ach to be released?
Ca++
What are the proteins called on the axon terminal that the vesicle binds to for it’s exocytosis?
SNARE proteins
What drug blocks SNARE proteins?
Botulinum toxin (Botox!)
After Ach does its thanggg on the postsynpatic cell, what enzyme degrades it?
Acetylcholinesterase
What is an example of a drug that inhibits acetylcholinesterase, thus increasing [Ach] in the synapse?
Physostigmine
Are nicotinic Ach receptors ligand or G-protein coupled?
Ligand
Where are nicotinic(m) Ach receptors?
Skeletal muscle
Are muscarinic Ach receptors ligand or G-protein coupled?
G-protein coupled
Are M1 receptors excitatory or inhibitory?
Excitatory
Where are M1 receptors?
Autonomic ganglia, CNS
Where are M2 receptors?
heart
Are M2 receptors excitatory or inhibitory?
Inhibitory
What is the mechanism of action of M2 receptors?
Gi coupled (inhibits AC)
Where are M3 receptors?
Smooth muscle
Are M3 receptors excitatory or inhbitory?
Excitatory
What is the mechanism of action of M1 and M3 receptors?
Gq coupled (PLC/IP3/DAG)
Where are nicotinic(n) receptors?
CNS postganglionic cell body and dendrites