title: Blood and urine 5-hydroxytryptophan and 5-hydroxytryptamine levels after administration of two 5-hydroxytryptamine precursors in normal man.
abstract: Six healthy male subjects received equimolar amounts of two 5-hydroxytryptamine (5-HT) precursors, 5-hydroxy-L-tryptophan (5-HTP) and gamma-L-glutamyl-5-hydroxy-L-tryptophan (glu-5-HTP), on two occasions in a randomised cross-over study. There were marked increases in urinary 5-HTP and 5-HT excretion after infusion of both compounds. Mean urinary excretion rate of 5-HT, which was < 0.7 nmol min-1 before dosing, rose to a peak value of 412 +/- 92 nmol min-1 at the end of 5-HTP infusion and 303 +/- 29 nmol min-1 after administration of glu-5-HTP. This occurred without significant changes in blood 5-HT levels measured in platelet-rich plasma. These findings provide further evidence that the increase in urine 5-HT after administration of both 5-HT precursors is largely due to 5-HT synthesised within the kidney.
authors.affiliation: Department of Medicine, Royal Infirmary, Edinburgh.
authors.forename: T C
authors.initials: TC
authors.lastname: Wa
authors.forename: N J
authors.initials: NJ
authors.lastname: Burns
authors.forename: B C
authors.initials: BC
authors.lastname: Williams
authors.forename: S
authors.initials: S
authors.lastname: Freestone
authors.forename: M R
authors.initials: MR
authors.lastname: Lee
mesh_terms: D006916:5-Hydroxytryptophan / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology* / Q000652:urine; D000328:Adult; D018592:Cross-Over Studies; D004151:Dipeptides / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D011355:Prodrugs / Q000008:administration & dosage / Q000494:pharmacology*; D012701:Serotonin / Q000097:blood* / Q000652:urine
chemical_list: D004151:Dipeptides; D011355:Prodrugs; C083320:gamma-glutamyl-5-hydroxytryptophan; D012701:Serotonin; D006916:5-Hydroxytryptophan