Noradrenergic Transmission Flashcards
Catecholamine compounds are composed of what?
Catechol moiety and amino acid side chain
What are some examples of catecholamines?
Norepinephrine, Epinephrine, Dopamine, and Isoprenaline.
What is the enzyme that changes tyrosine into DOPA?
Tyrosine hydroxylase, is the rate limiting step.
Tyrosine, DOPA, and dopamine are all found where in the nerve terminal?
In the cytoplasm.
Dopamine becomes Norepinephrine where within the nerve terminal?
Dopamine is taken into a vesicle by VMAT.
What is the enzyme that converts norepinephrine into epinephrine?
N-methyl transferase
N-methyl transferase is only found in?
Adrenal medulla
NE is also stored with what molecules?
ATP and NPY
What triggers the release of NE by exocytosis?
Action potential signals for Ca2+ uptake, which allows NE to be excreted.
What is NE release controlled by?
alpha receptor 2 negative feedback. (located on presynaptic terminal)/
NE is take up by what molecules?
NE transporter (NET) and OCT transporters
How much NE is take up by NET?
70% - 80%
Which molecule takes up circulating Epi?
OCT transporters
Once NE is taken up by NET, what occurs to it?
NE is metabolized by MAO in the neuronal cytoplasm.
Once NE is taken up by OCT, what occurs to it?
NE is metabolized by MAO and COMT
