ANS Flashcards
action of hemicholinium
prevents Ach uptake
ratelimiting step
botulinum MOA
Prevents fusion of ca with vesicles and hence inhibit release
cardiac muscurinic recep?
M2
Gi
M1,M3=Gq
M1 found in?
gastric parietal cells
mecamylamine acts on
selectively blocks Nn
atracurium=Nm
xerostomia due to irradiation
pilocarpine
also in Sjorgen syndrome-dry mouth and eye
druh used in emergency lowering of both open and close angle glaucoma
pilocarpine
bathenecol used for
major actions on smooth muscles of
bladder- atonic bladder
intestine- neurogenic atony ,megacolon ,
Achesterase inhibitors used in alzhiemer
tacrine(hepatotoxicity)
donepizil
gelantamine
rivastigmine
which of he following can cross BBB
physo/ neostigmine
physostigmine
-so can be used to reverse excess of centrally acting antimuscurinic.
what is ecthiophate
irreversible inhibitor of Ach-estrase
attach via its phoaphate group
once loss of alkyl group occurs(aging) pralidoxime ll not be able to reverse it .
what are the disadvantages of pralidoxime
- works before aging of enz takes place
- at higher doses has AchE inhibiting property
- cannot reverse reversible AchE inh action.
Why people on MOA inhibitors should avoid cheese and wine
To prevent hypertensive crises /cheese effect.
Due to inhibition of mao-a in gut lot of tyramine will enter into circulation.
Tyramine being a releaser will lead to release of massive amounts of NE leading to hypertensive crises.
Moa of botulism toxin
Binds to synaptobrevin on nerve terminal and prevent release of ach
What is pKa
It is the the ph at which the drug is 50% ionised and 50% nonionised
What are different types of M receptors
M1:secretion from git glands especially H + leading to gastric ulcer
M2: heart (AVN and SAN)
M3: all smooth muscles of body
Nicotinic receptors
Nn:found at adrenal medulla and autonomic ganglia
Nm:found on the skeletal muscles
Ventricular muscles of heart are under the control of which part of ANS
Sympathetic leading to inotropic response
PANS only innervate SA and AVN tissue
SANS innervates both nodal and musculature
All glands of the body have M3 receptors except
GIT which have M1 receptora
Effect of Ach on vessels
Act on M3 receptirs in endothelium of blood vessels -production of NO- diffusion into smooth muscle cells- vasodilation
Why indirect muscurinic receptor agonists have no effect on blood vessels
Because M3 receptors are not innervated so there is not any nerve terminal on which the drug can act
Second messenger of M and N receptors
M1/3:Gq-inc phospholipase C -inc IP3,DAG ,Ca
M2:Gi
Nn Nm: no second
