Autonomic and NMJ Pharmacology Flashcards
What is a NMJ?
The connections between the efferent motor neurone and the skeletal muscle
What happens to acetylcholine after it reaches the nicotinic receptor?
It is broken down by acetylcholinesterase into acetate and choline which is taken back up by the neurones and recycle into new ACh into vesicles
What does hemicholinium do?
Inhibits choline transport
What does black widow spider venom do?
Block voltage gated Ca ion channels
What does botulinium toxin do?
Block vesicle fusion
What does d-tubcararine do?
Use non-depolarising nicotinic receptor blockers
What does succinylcholine do?
Use depolarising nicotinic receptor blockers
What does 3,4-aminopyridine do?
Prolongs the action potential
When are non-depolarising or depolarising blockers used for paralysis?
- Surgical procedures
- Electroconvulsive therapy
- Controlling spasms in tetanus
When is botulinum toxin used?
- Treating muscle spasms
- Cosmetic procedures
When is anti-cholinesterase used?
- Treating myasthenic syndromes
- Reversing action of non-depolarising blockers
What does hexametheneum do?
Block ACh activated channel
What does mecylamine do?
Non-depolarising nicotinic receptor blocker
What does suxamethoneum do?
Depolarising nicotinic receptor blockers
Ganglionic transmission
How can transmission be increased at synapses?
Nictotine
What are the clinical applications for ganglionic transmission?
Next to none as there are too many widespread side effects
What is atropine?
Muscarinic receptor antagonist
What are examples of muscarinic receptor agonists?
- Carbachol
- Pilocarpine
What do muscarinic agonists do?
Mimic the effect of the parasympathetic system
What do muscarinic antagonists do?
Block the effects of the parasympathetic system
What is pilocarpine used for?
Used in the treatment of glaucoma: high intra ocular pressurre
What does pilocarpine do?
It contracts the ciliary muscle supporting the lens and seems to pen up the trabecular network through which the aqueous humour drains and/or the sphincter muscle of the iris contract which has the same effect
What does carbidopa do?
Block the enzymes that produce NA
What does reserpine do?
Block the transporter that fills the vesicles with NA
What does methyldopa do?
Introduces a false transmitter
or activates inhibitory presynaptic autoreceptors
What do doxazosin and propranolol do?
Block a or B postsynaptic receptors
How is tyrosine converted to NA?
- Tyrosine to DOPA using tyrosine hydroxylase
- DOPA to dopamine using dopa decarboxylase
- Dopamine to NA using dopamine hydroxylase
What enzyme does carbidopa block?
Dopa decarboxylase
What do amphetamines ddo?
Stimulate NA adrenaline release
What does phenoxybenzamine do?
Inhibits uptake of NA into glia
What does cocaine and tricyclic antidepressants do?
Inhibits uptake of NA into neurones
What do phenylepinephrine and salbutamol do?
Activate postsynaptic receptors
What are the clinical applications for the postganglionic sympathetic transmission?
- a1 agonists used as decongestants and to dilate the pupil
- a2 agonists used in the treatment of hypertension
- B2 agonists used in treatment of asthma
- B1 antagonists in the treatment of hypertension, angina, cardia arrhythmias and glaucoma
