Cholinergic mechanism Flashcards
Both nicotinic and muscarinic receptor play a role in the dopamine reward pathway
T or F
T
The side effect of using succinylcholine as a nmj blocker is that?
succinylcholine can cause electrolyte imbalance/abnormalities
N1 nicotinic receptor is found in ___A___ while N2 nicotinic receptor is found in ____B____
A - muscle type
B - neuronal type
The type of receptors found on the adrenal medulla are the?
nicotinic receptor (n2)
nicotinic receptor subtypes in the brain influences cell migration, neuronal outgrowth and signaling pathway
T or F
T
List the muscarinic receptor subtypes and where they are found
M1 - cerebral cortex, salivary and gastric glands
M2 - smooth muscle and cardiac muscle
M3 - smooth muscle, salivary and gastric glands
M4/M5 - hippocampus and substantia nigra
All subtypes of muscarinic receptors are found in the CNS
T OR F
T
nicotinic receptors are what type of receptors
Ionotropic
nicotinic receptor channels consist of 5 heterogeneous subunits which allows ion to pass through when activated
T or F
F
5 homologous subunits
list the subunits that make up the nicotinic receptor channel
2 alpha subunits
1 Beta
1 gama
1 delta
Nb: the binding sites are located on the alpha subunits
The development of muscarinic subtype specific agonist/antagonist is difficult because?
The orthosteric binding pocket of the receptors are highly conserved
pirenzipine is a muscarinic agonist that is 44 times selective to M1 receptors than M2
T or F
F
it is an antagonist
darifenacin (a muscarinic antagonist) is selective to what type of muscarinic receptor and it is used to treat what?
M3 selective
overactive bladder
the contraction of smooth muscles of airway, ilium, iris, bladder are mediated by what receptors
M3 receptor
although M2 are usually co expressed with M3 in smooth muscles
Vagal release on the heart acts on what receptor exclusively
M2 receptors
exocrine secretion such as saliva and insulin is mediated by what receptor
M3 with a smaller role played by M1
in transgenic studies with mice, knocking out the M1 receptor gene produced what effect?
increase in locomotion and hyperactivity
reduced learning and memory
what receptor is expressed in the hypothalamus thermoregulatory center
M2
acts to bring down temperature
melanin concentrating hormone in hypothalamus feeding center posses what receptors
M3 receptors
dopamine mediated locomotor movements are inhibited via what receptor
M4
The 2nd messenger for M1 and M3 is?
Ip3 and DAG
M1 and M3 activate phospholipase C which activates this 2nd messengers
M2 receptors act by inhibiting what enzyme
adenylate cyclase
which means it can’t catalyze production of CAMP leasing to low CAMP
ipratropium and tiotropium are what kind of antagonist and what are they used to treat
muscarinic antagonist
use to treat chronic obstructive pulmonary disorder(copd) and rhinorrhea (runny nose)
Bethanecol is an example of what kind of agonist
direct acting muscarinic agonist
pilocarpine is an example of what kind of agonist
direct acting muscarinic agonist
carbachol is an example of what kind of agonist
direct acting nicotinic AND muscarinic agonist
list 2 direct acting nicotinic agonist
nicotine
succinylcholine
physostigmine
pyridostigmine
neostigmine
edrophonium
are all examples of what kind of cholinergic ligand
reversible indirect acting cholinergic agonist
nb: indirect agonist affect both muscarinic and nicotinic receptor because they are actually inhibiting acetylcholinesterase found in both
the 3 reversible indirect cholinergic agonists used to treat alzheimer are:
donezepil
galantamine
rivastigmine
T or F
T
an example of a irreversible indirect cholinergic agonist is?
echothiophate
irreversible because they irreversibly bind to acetylcholineesterase thereby permanently disabling it from ending the action of ach on receptors
list the complications that may arise from muscarinic agonist
SLUDWARMF
Sweating
Lacrimation
urination
diarrhea
wheezing
accommodation
rhinorrhea
miosis
fasciculation
list 2 neuronal type nicotinic antagonist
mecamylamine
nicotine(at high doses)
At low dose nicotine acts as a __A___
while at high dose it acts as a ___B___
A direct nicotinic agonist
B neuronal nicotinic antagonist
pancuronium
vecuronium
rocuronium
atracunium
tubocurarine are examples of
muscle type nicotinic antagonist
Substrate site is also known as
Orthosteric site
