Pharm- 13 Flashcards
Which enzyme converts Tyr –> L-DOPA?
Tyrosine hydroxylase
Which AA makes dopamine?
Tyr
What is special about tyosine hydroxylase as far as the synthesis steps?
Its the rate-limiting step
What 2 substrates does tyrosine hydroxylase use to make L-DOPA from Tyr?
BH4 and O2
What enzyme converts L-DOPA –> Dopamine?
dopamine decarboxylase
What cofactor does dopa decarboxylase need?
PLP
Define: used to move a majority of DA back into the presynaptic cell; it’s a 12 transmembrane domain protein belongs to a family of catecholamine reuptake pumps
Dopamine Transporter (DAT)
True or false: Dopamine uses secondary active transport to get into the presynaptic cell.
True
What molecules does DA enter with into the cell throguh DAT?
Na+ and Cl-. (Na is the 1 that is made from the secondary active transport usign the Na/K ATPAase)
What transporter puts DA back into the synaptic vesicle?
VMAT
What 2 enzymes break down DA in the persynaptic terminal cytosol?
MAO and COMT
Which form of MAO (MAO-A or MAO-B) can degrade DA?
TRICK QUESTION LOL. Both can degrade DA.
Where is MAO-A expressed, brain or periphery?
GOT U AGAIN. ITS BOTH AHAHAHAHA
Where is MAO-B expressed, brain or periphery?
Just the brain.
So MAO-B inhibitors inhibit the breakdown of dopamine where?
CNS
What weird molecule in wine and cheese increases if you’re taking an MAOi?
Tyramine
Where is COMT expressed?
Brain, heart, liver and kidneys
The breakdown of DA from COMT and MAO’s break it down into which molecule?
HVA
Where can you test HVA to see the rate of DA breakdown?
Pee pee
D1- metabotropic or ionotropic
metabotropic