Week 3: Catecholamines-Tokes Flashcards
What is the MPTP model for Parkinson disease?
- MPTP is a side product from synthesis of Demerol, that is taken up by only dopaminergic neurons using a transport mechanism unique for these neurons
- MPTP converted by MAO-B to toxic product that kills DA neurons–>Parkinson like syndrome
Describe the short and long term regulation of TH activity.
- Short term: phosphorylation and dephosphorylation
- long term: transcriptional regulation by extra cellular stimuli such as NT, hormones, caffeine and nicotine
What enzyme converts L-DOPA to dopamine?
Dopa decarboxylase or AAADC/AADC
- vit B6 or pyridoxal phosphate is a cofactor
- enzyme present in excess
What activity or levels appear to be increased in schizophrenic patients?
Dopa decarboxylase (which produces 2-phenylethylamine) activity is increased -2PEA levels are also increased
Smoking can inhibit the activity of which enzyme?
MAO B, may be relevant to smoking addiction
In breaking down catecholamines, MAO action is followed by which enzyme?
-first aldehyde reductase, then aldehyde dehydrogenase
What is the significance of inhibiting COMT?
-inhibitors of COMT have some significance in treating Parkinson’s disease
What is the principle metabolite from DA after the action of MAO and COMT, followed by aldehyde dehydrogenase?
Homovanillic acid (HVA)
What enzyme produces NE from dopamine?
Dopamine beta hydroxylase
What enzyme produces epinephrine?
phenylethylamine-N-methyl transferase
What is the central area where dopamine rush is associated with drugs and other addiction?
Nucleus accumbens
What does cocaine inhibit?
DAT transporter
What is pargyline?
effective inhibitor of MAO
What genes are associated with susceptibility to delusional disorder?
multiple genetic polymorphisms of human D4 receptor, including 12 base pair repeat in exon 1
What is chemical sympathectomy?
-neuron specific toxins with homologous structures to catecholamines can be taken up by neurons
