Serotonin agonists and antagonists Flashcards
1
Q
What enzyme catalyzes the conversion of L-tryptophan to 5-HTP?
A
Tryptophan hydroxylase (TPH).
2
Q
What cofactor is required for TPH activity?
A
Tetrahydrobiopterin (BH₄).
3
Q
What G-protein do 5-HT1 receptors use, and what is their primary signaling effect?
A
Gi/Go (inhibitory); decrease cAMP by inhibiting adenylyl cyclase.
4
Q
Which G-protein pathway do 5-HT2 receptors activate, and what second messenger increases?
A
Gq pathway; stimulates phospholipase C (PLC), increasing intracellular Ca²⁺.
5
Q
Why might a vitamin B₆ deficiency impair serotonin synthesis?
A
Vitamin B₆ is required to form pyridoxal phosphate (PLP), a cofactor for AADC, the enzyme that converts 5-HTP to serotonin.
