BMS03-1023 Pharmacology of Cholinergic Transmission Flashcards
How does the PNS reach the salivary glands?
Axon Acetylcholine Nicotinic receptor Axon Acetylcholine Muscurinic receptor
How does the SNS reach the adrenal medulla?
Axon
Acetylcholine
Nicotinic receptor
How does the SNS reach the sweat glands?
Axon Acetylcholine Nicotinic receptors Axon Acetylcholine Muscurinic receptors
How does the SNS reach the blood vessels?
Axon Acetylcholine Nicotinic receptor Axon Noradrenaline
How does the somatic efferent system reach the muscles?
Axon
Acetylcholine
Nicotinic receptor
What do pre-synaptic drugs affect?
Synthesis
Storage
Release
What do post-synaptic drugs affect?
Receptors
Removal mechanisms
What is cholinergic transmission?
Involves acetylcholine activating a nicotinic and muscarinic receptor
What forms ACh?
Choline and acetylcoenzyme A using the choline acetyl transferase enzyme
Hemicholiniums
Block entrance of choline so ACh cant be made
How does ACh affect nicotinic receptors?
Binds both the alpha sub units which opens the channel and depolarises membrane
What moves through nicotinic receptors?
Non selective for positive ions, mainly Na and K
Do all nicotinic receptors have the same structure?
No, muscles and ganglionic receptors differ meaning drugs can be more selective
What are the units of the muscle ones?
2 alpha
Beta
Omega
E
What are the units of the ganglionic ones?
2 alpha
3 beta
Are the drugs acting on nicotinic receptor agonists or antagonists?
Agonists
Describe a muscle relaxant
These are reversible competitive antagonists at the nicotinic receptor, they have affinity but no efficacy so the receptor cant be activated
Name drugs which act as nicotinic ganglion blockers and what disease they combat
Reduce blood pressure and bleeding
Trimetaphan
Hexamethonium
How does botox work?
Kills protein involved in exocytosis so ACh cant be released
What can botox treat?
Over active bladder
Headache
Spasticity
What are he 3 main subtypes of muscarinic receptors?
M1, 2 and 3
What do muscarinic agonists mimic the effects of? Give 2 examples
PSN
Pilocarpine (eye drops for glaucoma)
Bethanacol (stop urine retention)
What does pilocarpine do to treat glaucoma?
Constrict pupil and contract ciliary muscle so the lens is more sphere improving near vision
Name some muscarinic receptor antagonists and how they work
Atropine treats bradycardia
Tiotropium treats asthma
Tropicamide dilates pupils
