<prompt> Serotonin is a derivative ofTryptophanTyrosinePhenylalanineMelatonin  <response>: A Tryptophan SEROTONIN 5-hydroxytryptamine, 5 HT, produced from tryptophan is important in mere impulse transmission neurotransmitter It regulates sleep, behaviour, blood pressure etc. Hydroxylation of tryptophan to 5-hydroxytryptophan is catalyzed by liver tyrosine hydroxylase. Subsequent decarboxylation forms serotonin 5-hydroxytryptamine, a potent vasoconstrictor and stimulator of smooth muscle contraction. Catabolism of serotonin is initiated by monoamine oxidase MAO catalyzed oxidative deamination to 5-hydroxindoleacetate, which humans excrete in their urine 2-8 mgd The psychic stimulation that follows administration of iproniazid is attributed to its ability to prolong the action monoamine oxidase Serotonin or 5-hydroxytryptamine 5 HT is a neurotransmitter, synthesized from tryptophan. Normally, about 1 of tryptophan is converted to serotonin The production of 5HT occurs in the target tissues. 