Possible Interaction: 5-Hydroxytryptophan and Serotonin

“ L-5-Hydroxytryptophan acts to inhibit panic, which supports a modulatory role of serotonin in panic disorder.”

“Increasing 5-HT concentration in milk via inhibiting its reuptake (SSRI), or by increasing the precursor for 5-HT synthesis 5-hydroxytryptophan , accelerated decline in milk synthesis at dry-off.”

“In general, these supplements appear to act as GABA receptor agonists or to boost GABA levels, although Kava inhibits both norephinephrine uptake and sodium and potassium channels and 5-HTP may act through elevation of serotonin.”

“administration significantly potentiated the mouse head-twitch response induced by 5-hydroxytryptophan (5-HTP, a metabolic precursor to serotonin ), and also, decreased the immobility time in mouse tail suspension test, which was completely prevented by p-chlorophenylalanine (PCPA, an inhibitor of serotonin synthesis) pretreatment.”

“Increasing 5-HT concentrations by injection of 5-hydroxytryptophan (Tulunay et a1 1976) potentiates morphine-induced antinociception.”

“Several studies have suggested that exogenous administration of the serotonin precursor 5‐hydroxytryptophan (5‐HTP) can result in the ectopic production of serotonin in dopaminergic neurons and a concomitant reduction in dopamine release.”

“In this review, we address the possible role of the essential amino acid L-tryptophan or its metabolic derivative 5-hydroxytryptophan in the modulation of serotonin (5-hydroxytryptamine) synthesis and thereby in affecting the pathophysiology of central and peripheral nervous system disorders, including depression and irritable bowel syndrome.”

“In competition studies, 5-HT had high affinity for 5-HT1A and 5-HT2C sites in the brainstem and cortex, but L-5-HTP was > 1,000-fold less active.”

“Supplementing milk replacer with 5-hydroxytryptophan (serotonin precursor) or fluoxetine (reuptake inhibitor) increases serotonin bioavailability.”

“Treatment with fluoxetine or 5-hydroxytryptophan significantly increased intracellular serotonin concentrations and subsequently increased PTHrP gene expression, which was reduced with transglutaminase inhibition.”