Biogenic amines play an important role in brain metabolism and functioning, participation synaptic transmission as neurotransmitters neuromodulators (dopamine, serotonin, histamine others). Catecholamines are formed from the essential amino acid phenylalanine by hydroxylating it to tyrosine with enzyme phenylalanine-4-hydroxylase, which is subsequently converted dioxyphenylalanine (DOPA) tyrosi...