p-Ethynylphenylalanine (4-Ethynyl-L-phenylalanine) is a potent, selective, reversible and competitive inhibitor of tryptophan hydroxylase (TPH), with a Ki of 32.6 μM.IC50 & Target: Ki: 32.6 μM (TPH)In Vitro: p-Ethynylphenylalanine selectively and reversibly inhibits the biosynthesis of serotonin.
p-Ethynylphenylalanine has a low affinity for various recombinant 5-HT receptors (5-HT1, 5-HT2, 5-HT4, 5-HT5, 5-HT6, and 5-HT7).
In Vivo: p-Ethynylphenylalanine (30 mg/kg; i.p.) decreases in 5-HT and 5-HIAA levels in the rat midbrain but not in tissue.
p-Ethynylphenylalanine does not inhibit the aromatic amino acid decarboxylase.