Adnergic Nervous System Flashcards
What is the main neurotransmitter of the adrenergic synapse
Norepinephrine
What do all catecholamines have
amine group, benzene ring with two hydroxy groups ortho to one another
What structures are essential for binding to adernergic receptors
hydrogen bonding and pi-pi stacking from the catechol, ionic binding of the amino group, hydrogen bonding of the hydroxy group at the beta carbon
What are the two amino acids that are needed for biosynthesis of norepinephrine
Phenylalanine and tyrosine
T/F: Tyrosine is an essential amino acid (not made in the body) that is converted to phenylalanine to create catechols
False: Phenylalanine is an essential amino acid that is converted to tyrosine to create catechols
What is the enzyme that converts phenylalanine to tyrosine
L-phenylalanine hydroxylase
What is the rate limiting step enzyme for creating catechols, what is the MOA and result
L-tyrosine hydroxylase, adds a hydroxy group ortho to the other hydroxy group to create a L-DOPA (a catechol)
What is the inhibitor L-tyrosine hydroxylase, what kind of inhibition is it
alpha-methyltyrosine, competitive
What enzyme converts L-DOPA into a neurotransmitter, what neurotransmitter is L-DOPA converted to
L-aromatic amino acid decaboxylase, Dopamine
What are the two inhibitors of L-aromatic acid decarboxylase, which is used in combination with L-DOPA for parkinson’s disease
alph-methyldopa (aldomet) and Carbidopa, carbidopa
What is the enzyme that converts Dopamine into the adnergic neurotransmitter, what is this neurotransmitter
Dopamine Beta hydroxylase, norepinephrine
T/F: Vitamin C is a cofactor for dopamine Beta hydroxylase to create norepinephrine
True
What enzyme converts norepinephrine to epinephrine
Phenylethanolamine N-methyl Transferase (PNMT)
What are the two amino acids that deactivate, what is the MOA of each
MAO: turns amino group into an aldehyde, COMT: adds a methyl group to one of the hydroxy groups
T/F; COMT and MAO only deactivate norepinephrine and epinephrine
False: Both enzymes can deactivate dopamine as well
Why is COMT so essential to protecting the body
prevents ortho-quinones from forming since they are easily oxidized
What are two common inhibitors of COMT
Entacapone and Tolcapone
How are norepinephrine responses terminated
reuptake via norepinephrine transporter
What enzyme repackages norepinephrine
Vesicular monoamine transporter (VMAT)
What drug limits uptake of norepinephrine
Risperdone
T/F: Adernergic receptors are G coupled protein receptors that are slightly different because binding happens in the cleft of the receptor
True
T/F: Alpha 1 adernergic receptors can still have substrates bind even if it is not a catechol, while Alpha 2 cannot
True
How does Alpha 1 adernergic activity become lost on a chemical structure
Adding a substituent to the alpha carbon
Which drug is a prodrug for methoxamine analogue and is an alpha 1 agonist
Midodrine
