to investigate systemic serotonin ( 5-ht ) metabolism in migraine , we determined platelet and platelet-free plasma concentrations of 5-ht , its precursors tryptophan and 5-hydroxytryptophan , and its main metabolite 5-hydroxyindoleacetic acid ( 5-hiaa ) , as well as the activities of the platelet enzymes monoamine oxidase and phenolsulfotransferase in classic and common migraineurs .
C0041249
tryptophan
C0000578
5-hydroxytryptophan