Neuropharamcology Flashcards
What are cotransmitters in the SNS?
ATP, galanin, neuropeptide Y
What is the RLS in neurotransmitter production?
Tyrosine–>Dopa via tyrosine hydroxylase. Can be up or down regulated by stress levels
What enzyme converts norepinephrine to epinephrine? What upregulates this enzyme?
Phenylethanolamine N methyltransferase (PNMT). GCs from the adrenal cortex upregulate the enzyme (ie stress)
How does the adrenal medulla come into play with NTs?
Adrenal medulla has two types of cells. Those with PNMT and those without. NE diffuses from granules in the medulla, gets methylated in the cytoplasm, then re-enters granules as epinephrine.
What pump takes up catecholamines in cytoplasm and puts them in vesicles?
VMAT
What is calcium’s role in NT release?
Interacts with VAMPs triggering fusion of the vesicle and ell membrane
GCPRs alpha and beta and their G proteins…
Alpha 1: Gq
Alpha 2: Gi
Beta 1&2: Gs
What are the factors determining actions of sympathomimetic amines?
- Potency
- NE and E are very potent in activation of alpha/beta - Proportion and density of receptors
- More there are, more response will have - Reflex or homeostatic adjustments
- Brain says calm down - Refractoriness/desensitization of the receptor
- Either beta arrestin causes receptor to be internalized or the ligand to lose its affinity for the receptor
Describe the NT reuptake systems
Uptake 1:
- NT reuptake into nerve endings
- Saturated easily
- High affinity, low capacity
Uptake 2:
- NT reuptake into extra-neuronal areas
- Low-affinity, high capacity
Alpha-methyldopa
Drug that inhibits LAAD (dopa–>dopamine blocked)
Carbidopa
Drug that inhibits LAAD in the periphery, will not cross the BBB
Disulfiram
Inhibits dopamine beta hydroxylase (dopamine to NE) and inhibits ALDH
Reserpine
Blocks VMAT uptake of dopamine into vesicle
L-DOPA
Synthetic DOPA to use as precursor to dopamine in parkinson’s patients
Bromocriptine
Selective agonist for D2 receptors tx for parkinson’s
