L9 - drugs affecting PNS Flashcards
what is the NT at all ganglia
ACh
what is the NT in all of the PNS
ACh
what is the NT in the post ganglionic SNS
NA
ACh in sweat glands
what is the receptor at all ganglia
nicotinic ACh
what is the NT in pre ganglionic synapses
ACh
what type of receptor are nicotinic
ligand gated ion channels
what type of receptor are muscarinic
G protein coupled
where are muscarinic receptors? give examples
all post ganglionic PNS synapses
also sweat glands of SNS
salivary glands, GI tract, bladder, lungs , heart
how is ACh synthesised
choline + acetyl CoA via CAT enzyme
how does ACh get into neuron
carrier against conc gradient
where are NAChR’s located
NMJ and ganglionic
how many muscarinic receptors are there
M1 - M5
which of the Muscarinic receptors are Gq linked
M1 - M3 - M5
where are M3 found
smooth muscle
salivary glands
vasoconstriction
(activation increases both)
where are M1 found and what do they do
GI tract
increase GI secretion
what muscarinic receptors are Gi/o linked
M2
what do the Gi/o linked ACh M2 receptors mediate
slowing of HR (atria)
neuronal inhibition
list some effects of muscarinic agonists
- slowed HR
- smooth muscle contraction
- sweating
what are nicotinic receptors permeable to
K+ Na+
what is the difference between ACh effect at the NMJ and in the ANS
- at the ANS it causes AP at the post synaptic membrane
2. in the NMJ an end plate potential has to be reached before an AP is generated
what types of enzymes are AChE’s
serine hydrolases
what are the names of the 2 regions in the active site of AChEs
anionic site
esteratic site
role of anionic site in active site of AChE’s
binds to choline
is neostigmine or edrophonium longer lasting?
neostigmine
effects of AChE inhibitors
- increase all PNS activity (bradycardia, salivary&GI secretions, smooth muscle contraction)
