10 - NM Blocking Drugs Flashcards
Where do NM drugs act?
NOT in the autonomic nervous system. In the somatic nervous system.
alpha motor neurons (cell body)
vertebral column, ventral horns
single axons innervating muscles
Outline the process of transmission
Choline acetyltransferase synthesizes ACh from choline + Acetyl CoA
Packaged in vesicles AP (opening of VSCCs) Exocytosis Receptors on endplate region Influx of Na+ (endplate potential) (graded potential) - all or nothing AP
The endplate region is approximately in the middle of skeletal muscle fibre
Acetylcholinesterase breaks down NT
Are somatic nAChRs the same as ganglionic ones?
No
This has allowed drugs with a degree of selectivity to have been produced
Especially applies to antagonists
a1, a2, b1, y, d subunits in receptor
2ACh molecules need to bind (one to each alpha subunit)
Give some examples of drugs that target somatic nAChRs
Tubocurarine, Atracurium - competitive
Suxamethonium - depolarizing