autonomic nervous system 3 Flashcards
adrenergic synapses
noradren
co transmitters: ATP and NPY
Noradrenaline is a what and what is it formed from
catecholamine
made from tyrosine
NT synthesis what happens to tyrosine to get nor and dopamine
turned into dopa by tyrosine hydroxylase
the dopa to dopamine by dopa decarboxylase
then dopamine to noradren by dopamine - beta- hydroxylase
noradrenaline inhibits what
inhibits TH tyrosine hydroxylase
rate limiting step is
tyrosine to dopa
drugs affecting NT synthesis
alpha- methyl tyrosine what does it affect
inhibits tyrosine hydroxylase
drugs affecting NT synthesis
what affects dopa decarboxylase
disulfiram cu2+ chelators
L-dopa - treatment parkinsons increases dopamine
NT storage what stores them
VMAT
vesicular monoamine transporter
drugs affecting NT storage
reserpine
depletes Noradren stores previously used to treat hypertension cause serve depression
NT release how does it happen
ca influx
vesicle fusion with membrane
nt release
how is NT regulated without drugs
auto-inhibitory feedback
some evidence of positive feedback via Beta 2 Receptor
Neurotransmission regulated by Drugs
what are the indirectly acting sympathomimetics
amphetamine
tyramine
ephedrine
amphetamine what does it do
displaces Nad from vesicle
increasing Nad transmission
cns stimulant
tyramine what does it do
increases Nad release from vesicle
no clinical use
ephedrine
beta agonist
increases Nad transmission
nasal decongestant
Nt reuptake and degradation
what does this
NET- noradrenaline transporter or EMT - extraneuronal monoamine transporter then VMAT packaging or degraded by MAO or catechol-o-methyl transferase COMT
breaking down only happens is Nor is
in excess
MAO where is it located and what forms does it contain
located in mitochondrial surface
2 distinct isoforms MAO-A or B
found in Nor terminals or in liver/intestines
MAO what does it do
converts catecholamines to aldehyde
can act of 5-ht and dopamine
controls levels of Nor in CNS terminals
COMT where is it located
located in cytosol
not found in nor terminals but found in adrenal medulla
COMT what does it do
converts catecholamines to methoxylation
drugs that act on reuptake and degradation
MAOIs
amphetamine, tyramine, ephedrine
methylphenidate, atomoxetine
