Neuropharmacology Flashcards
what are cholinergic drugs?
drugs that mimic the action of acetylcholine
what are adrenergic drugs?
drugs that mimic the action of epinephrine and norepinephrine
what are the general functions of the sympathetic and parasympathetic systems?
oppose each other
discrete vs diffuse action
both excitatory and inhibitory
maintain homeostasis
one may directly inhibit other
what are the events involved in a cholinergic response?
synthesis of acetylcholine
storage of acetylcholine in vesicles
arrival of impulse and calcium uptake
release of acetylcholine into synaptic cleft
interaction of acetylcholine with receptor
hydrolysis of acetylcholine by esterase
reuptake of choline
what are the agonist and antagonist of muscarinic receptors (subtype of cholinergic)?
muscarine is agonist
atropine is antagonist
what are the agonist and antagonist of nicotinic receptors (subtype of cholinergic)?
nicotine is agonist
curare is antagonist
nicotinic receptor is the _________________ and is activated by _____________________________________
sodium channel
2 acetylcholine binding to the 2 alpha subunits
what are the subclasses of muscarinic receptors?
M1
M2
M3
where are M2 receptors located?
heart
where are M3 receptors located?
smooth muscle
secretory glands
what is the receptor action of M1 and M3?
M1: close potassium channel
M3: increased contraction, increased secretion
depolarization
what is the M2 receptor action?
open potassium channels and decrease cAMP to decrease heart rate
if a cholinergic drug’s mechanism of action is at M1, what does it do?
excitatory
close potassium channel
activate phospholipase C
if a cholinergic drug’s mechanism of action is at M2, what does it do?
inhibitory
open potassium channel
inhibit adenylate cyclase
if a cholinergic drug’s mechanism of action is at M3, what does it do?
excitatory
activate phospholipase C
increase ionized calcium concentration
where are cholinergic actions in the body?
cardiovascular system
respiratory system
gastrointestinal system
urinary bladder
eye
skeletal and smooth muscles
what are cholinergic actions in the cardiovascular system?
decrease heart rate
decrease atrial contractility
decrease AV conduction
decrease blood pressure
what are cholinergic actions in the respiratory system?
bronchoconstriction
increase bronchial secretion
what are cholinergic actions in the gastrointestinal system?
increase motility
increase secretion
relax sphincters
what are cholinergic actions in the urinary bladder?
contract detrusor muscle
relax internal sphincter
what are cholinergic actions in the eye?
contract sphincter muscles and iris
contract ciliary muscle
what are cholinergic actions in skeletal and smooth muscles?
contraction: muscle spasms
what are some direct acting cholinomimetics?
natural alkaloids- muscarinic receptor
synthetic- choline esters
what are some natural alkaloids?
muscarine
pilocarpine
arecoline
what are some synthetic cholinomimetics?
choline esters:
carbachol
bethanechol
methacholine
how do indirect acting cholinomimetics work?
inhibit acetylcholinesterase