Print Email Facebook Twitter Bioavailability of tryptophan from a single oral dose of a trytophan-enriched peptide mixture in healthy men Title Bioavailability of tryptophan from a single oral dose of a trytophan-enriched peptide mixture in healthy men Author Brink, E.J. Boelsma, E. Steijns, J. Hendriks, H.F.J. TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO Publication year 2004 Abstract The aim of the study was to investigate the bioavailability of tryptophan (Trp) from a Trp-enriched peptide mixture in healthy men. A second objective was to investigate the effect of this Trp-enriched protein hydrolysate on potential parameters of serotonergic activity. serum serotonim melatonin and prolactin and urinary 5-hydroxyindol-acetic acid and 6-sulfatoxymelatonin. Glucose and insulin were measured as the placebo consisted of orange juice with added glucose. The study was a randomised, double blind, placebo-controlled, four-way crossover trial in eight healthy male subjects. Treatments consisted of a single oral load of a Trp-enriched protein hydrolysate containing 500 mg L-Trp, 500 mg L-Trp plus addition of a mixture of amino acids having the same composition as in the hydrolysate, 500 mg L-Trp, and placebo. Before and after ingestion blood and urine were collected during a period of 4 hours. The Trp-enriched protein hydrolysate increased the plasma Trp/LNAA ratio by about 70% at 60 to 90 min after ingestion. AM three Trp treatments induced a comparable plasma Trp-response demonstrating that Trp is readily available for the body independent of whether it was peptide-bonded or in free amino acid form. None of the Trp treatments affected serum serotonim prolactin, melatonin and insulin concentrations, as well as urinary 5-hydroxyindol-acetic acid and 64-sulfatoxymelatonin concentrations during the 4-hour measurement period in the morning. Copyright © 2004 by New Century Health Publishers, LLC. Subject Biology HealthPhysiological SciencesAmino acidsDietary supplementsSerotonergic activityTryptophan5 hydroxyindoleacetic acid6 hydroxymelatonin o sulfateAlanineArginineAspartic acidCystineGlucoseGlutamic acidHistidineInsulinIsoleucineLeucineLysineMelatoninMethioninePhenylalanineProlactinProlineProtein hydrolysateSerineSerotoninThreonineTryptophanValineAdultAmino acid blood levelArea under the curveBlood analysisBrain functionChemical bindingClinical trialControlled clinical trialControlled studyCrossover procedureDouble blind procedureDrug bioavailabilityHumanHuman experimentInsulin blood levelMaleMetabolic parametersNormal humanProlactin blood levelRandomized controlled trialReviewSerotonin blood levelSerotonin brain levelSerotonin metabolismUrinalysisUrine level To reference this document use: http://resolver.tudelft.nl/uuid:782f9cf5-0a5c-44b0-aad4-d25306c5e068 TNO identifier 237923 ISSN 1540-7535 Source Current Topics in Nutraceutical Research, 2 (3), 169-176 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.