CATECHOLAMINES Flashcards
AMPT
blocks TH, decreases synthesis
VMATs purpose
load catecholamines into synaptic vesicles
VMATs blocked
by resperine, used for Huntington’s
Single spiking mode
action potentials at irregular intervals (tonic)
Burst mode
2-20 spikes at higher frequency (phasic)
MAO and COMT
catecholamine breakdown, produce metabolites
nonselective MAO inhibitors
used to treat depression but with dangerous side effects
HVA
DA metabolite
MHPG and VMA
NE metabolite
DA cell groups location
substantia nigra and VTA
dopamine deficient mouse
hypoactive
D1
stimulate adenylyl cyclase and increase cAMP synthesis (metabotropic)
D2
inhibit cAMP synthesis and regulate ion channels for K
DA receptor antagonist
suppress locomotor behavior
D2 antagonist
cause behavioral supersensitivity due to up regulation
DA transporter knockout animals
hyperactive
NE location
pons and medulla and LC
blood borne NE
sympathetic, fight or flight
adrenoreceptors
metabotropic
B1 and B2 receptors
stimulate adenylyl cyclase and enhance formation of cAMP
a2 receptors
inhibit adenylyl cyclase and reduce cAMP
a2 agonist
inhibit noradrenergic cell firing
a2 antagonist
blocks autoreceptors
passive avoidance learning
increase EPI and NE
Catecholamines synthesis
from tyrosine
rate limiting enzyme
tyrosine hydroxylase
B2 adrenoceptor agonist used for
COPD and asthma
a1 receptor agonist
phenylephrine, decongestant
