Possible Interaction: Tryptophan and N-Methyl-3,4-Methylenedioxyamphetamine

“At typical doses for each of these compounds, neurochemical studies suggest a continuum of serotonergic enhancement from tryptophan through the SSRIs, fenfluramine and MDMA having the largest effect.”

“Following MDMA administration, the same dose of tryptophan caused a smaller (26%) rise in brain serotonin whereas in blood it had no effect.”

“ Tryptophan modulated effects of several drugs on neuronal firing rates, including a selective 5-HT(1A) receptor antagonist (WAY-100635), a monoamine oxidase inhibitor (pargyline), a selective serotonin reuptake inhibitor (fluoxetine), and a serotonin-releasing agent ( methylenedioxymethamphetamine).”

“ Brain tryptophan hydroxylase activity decreases within 15 min after a single administration of 3,4-methylenedioxymethamphetamine.”

“Based upon IC50 values, L-tryptophan increased the potency of MDMA by approximately 3-fold.”

“Pretreatment with L-tryptophan (100 microM) lowered the doses of MDMA required to inhibit unit activity.”

“The question is raised as to what effect L-tryptophan may have on the psychotropic and neurotoxic actions of MDMA.”

“These studies suggest that MDMA and its congeners inactivate central tryptophan hydroxylase by inducing oxidation of key enzyme sulfhydryl groups.”

“Decreases in mouse central tryptophan hydroxylase activity, and prolonged decreases in mouse 5-hydroxyindole concentrations, were observed only after multiple doses of MDMA , suggesting that the duration of exposure may be an important determinant of toxic effects.”

“These results are in contrast to effects in rats, in which a single 10 mg/kg dose of MDMA induced immediate and prolonged decreases in both central tryptophan hydroxylase activity and 5-hydroxyindole concentrations.”