Biosynthesis & Termination of NT Flashcards
1
Q
From what and where is Ach synthesized?
A
from Acetyl CoA and choline
in cholinergic neuron axon terminal
2
Q
How is Ach stored?
A
in vesicles until AP hits
3
Q
How is Ach metab or terminated?
A
After dissociating from membrane, destroyed by metabolism instantly by AchE
(into choline and acetate, choline can re-enter axon and be recycled)
4
Q
How is NE terminated after dissociation?
A
- reuptake into presynaptic membrane (either metab by MAO in mitochondria or restored)
- metabolism in circulation (by COMT/MAO-B)
- metabolism by COMT in other tissues
- bind to a2 presynaptic R -> inhibiton of release
5
Q
How can Reserpine affect VMAT transporters?
transporters that take NE into vesicles
A
A reversible antihypertensive (reserpine) can inhibit the package of NE into the vesicles, leading to ↑ free NE that increases metabolism by the adrenergic vessels (↓ NE stores)
