ANS Cholinergic Flashcards
prototype that acts directly at both muscarinic and nicotinic receptors
Ach
prototype for the indirect acting cholinesterase inhibitors
neostigmine
Muscarinic mechanism of action
g protein and releases second messengers DAG and IP3. IP3 causes release of calcium from storage sites and causes smooth muscle contraction
Nicotinic mechanism of action
Ach receptor is located on channel protein that is selective for sodium and potassium. Receptor activation causes depolarization with influx of Na+ causes EPSP
drug that blocks synthesis of Ach
hemicholinium
drug that blocks storage of Ach
vesamicol
drug that blocks release of Ach
botulinum toxin
drug that block NE synthesis
metyrosine
drug that blocks catecholamine storage
reserpine
drug that blocks catecholamine release
guanethidine
drug that facilitates release of catecholamine
amphetamine
drug that impairs reuptake of catecholamines
cocaine
causes relaxation of skeletal muscle and systemic blood vessels
beta 2
causes contraction of skeletal muscle and systemic blood vessels
alpha 1
causes increase in heart rate
beta 1
causes relaxation of lungs and tracheal and bronchial smooth muscle
beta 2
short duration of action, quaternary structure , susceptible to pseudocholinesterase
direct acting cholinergic agonists
pilocarpine, bethanachol, methacholine
direct acting muscarinic agonists
Methacholine has the greatest muscarinic action on which system?
cardiac
2 drugs with very high selectivity to nicotinic receptors
Ach and pilocarpine
How do you reverse the effect of methacholine?
beta agonist
first cause depolarization at nicotinic receptor but then become antagonist
nicotinic receptor agonists
nicotine, succinylcholine varenicline
nicotinic receptor agonists
Effect of large dose of nicotine on NMJ
depolarization and depression of transmission, receptor desensitization
partial agonist of nicotinic receptors and receptor is mesolimbic nicotinic
varenicline