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Citrownklown t1_j5j2wpc wrote

Reply to comment by bicbrownboi in What is a neurotransmitter "turnover rate", with reference to acetylcholine? What does it mean if the turnover rate is increased or decreased? by yungPH

Good point.

AcCh turnover increase means more is degraded by the enzyme, decrease the opposite.

Depending on the location of the turnover (central nervous system or e.g. In skeletal muscles) this could lead to prolonged or shorter duration of AcCh.

One cool example of a drug working by decreasing AcCh effect (ultimately) is botox, leading to temperary paralysis on the injection site.

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curiousnboredd t1_j5k3zku wrote

iirc Botox causes muscle relaxation (opposite to tetanus which cause contraction) so wouldn’t that mean it causes a decrease in acetylcholine and increase in acetylcholiesterase?

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Citrownklown t1_j5kdjzt wrote

It looks like the mode of action of botox is a bit more complex (here’s from one of my favorite webpages drugs@fda)

12.1 Mechanism of Action BOTOX blocks neuromuscular transmission by binding to acceptor sites on motor or sympathetic nerve terminals, entering the nerve terminals, and inhibiting the release of acetylcholine. This inhibition occurs as the neurotoxin cleaves SNAP-25, a protein integral to the successful docking and release of acetylcholine from vesicles situated within nerve endings. When injected intramuscularly at therapeutic doses, BOTOX produces partial chemical denervation of the muscle resulting in a localized reduction in muscle activity. In addition, the muscle may atrophy, axonal sprouting may occur, and extrajunctional acetylcholine receptors may develop. There is evidence that reinnervation of the muscle may occur, thus slowly reversing muscle denervation produced by BOTOX.

https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/103000s5236lbl.pdf#page13

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