Catecholamines Flashcards
what are the type of the dopamine receptors
Dopamine receptors are GPCRs
what are the families of the D receptors
D1 Family
D2 Family
explain the D2 Family
D2, D3, D4
- couple with Gi (inhibitory)
- located on presynaptic and/or postsynaptic neurons
- greater affinity for dopamine (may mediate tonic transmission)
explain the D1 Family:
D1 and D5
- couple with Gs (excitatory)
- located on postsynaptic neurons
- lower affinity for dopamine (may require phasic transmission)
how does ADHD products work
Stimulant products that boost norepinephrine and dopamine
neurotransmission by inhibiting their re-uptake by presynaptic neurons
how does Methylphenidate work
Norepinephrine and dopamine reuptake inhibitor (NDRI)
- One of the first medications for ADHD (Ritalin)
- Higher affinity and likely more active for dopamine
how does Atomoxetine work
- Norepinephrine, dopamine, and serotonin reuptake inhibitor
- Relatively newer medication for ADHD (Strattera)
- Affinity for norepinephrine > serotonin > dopamine
what is the role of the dopamine in the schizo
Dopamine involved in the postulated pathology of schizophrenia.
- evidence for greater expression of the D2 receptors in patients
- efficacy of D2 receptor antagonist antipsychotics correlates
with D2 receptor affinity
how does haloperidol work
antagonist at DA > 5-HT receptors
- potential for extrapyramidal adverse effects
how does olanzapine work
antagonist at DA ~ 5-HT receptors
- lower potential for extrapyramidal adverse effects
what is the pathology of the Parkinson
- Progressive neurodegenerative disease
- Loss of dopaminergic neurons in the substantia nigra pars compacta
- Dysregulation of basal ganglia motor circuits
how does Levodopa (L-DOPA) work
- precursor to dopamine; has been used for decades
- majority of dose remains outside of the CNS, and conversion to
dopamine induces adverse effects (nausea and vomiting) - often co-administered with an aromatic L-amino acid decarboxylase
inhibitor that stays in the periphery (e.g. carbidopa)
what are the Dopamine agonists in the parkinson
pramipexole and ropinirole: agonists at D2, D3, and D4 receptors
- adverse effects: nausea, hallucinations
where does Norepinephrine (Noradrenaline) produces
– Locus Coeruleus
give two ex for SNRIs
Venlafaxine (Effexor)
Duloxetine (Cymbalta)
