a similar response was not elicited by the other indoles ( tryptophan , n-acetylserotonin , 5-hydroxytryptophan , melatonin , or 5-hydroxyindoleacetic acid ) or by the amines phenylephrine , isoproterenol , dopamine , or histamine ) .
C0041249
tryptophan
C0000578
5-hydroxytryptophan