title: The effect of sleep restriction and psychological load on the diurnal metabolic changes in tryptamine-related compounds in human urine.
abstract: OBJECTIVE
  The effect of a severely stressful situation (sleep restriction and psychological load) on the diurnal changes in novel tryptamine-related compounds (hydroxydiacetyltryptamine, sulphatoxymelatonin, and dihydromelatonin) was evaluated in human subjects for 16 days.
  
  
  METHODS
  The subjects were allowed to sleep for 5 h on days three through 12 and for 8 h on the other days. On days three through 12, the subjects were asked to perform a psychological task. The first two and the last 4 days were viewed as control days. A performance test was administered to evaluate the extent of the subjects' fatigue. Total urine was sampled by collecting it into bottles three times a day [(1) during the sleeping period, (2) in the morning, and (3) in the afternoon]. Seven tryptamine-related compounds in urine were assayed using HPLC-fluorometry.
  
  
  RESULTS
  The urine melatonin level was high at night and low during the day. In contrast, urinary levels of hydroxydiacetyltryptamine and sulphatoxydiacetyltryptamine were low at night and high during the day. Dihydromelatonin was undetectable in urine during the sleeping period. Sleep restriction and psychological load did not affect diurnal changes in urinary melatonin, hydroxydiacetyltryptamine, sulphatoxydiacetyltryptamine, or N-acetylserotonin levels. The concentrations of hydroxymelatonin and sulphatoxymelatonin in urine did not show diurnal changes and decreased gradually during the experimental days. A principal component analysis confirmed the diurnal changes and suggested two novel metabolic pathways: (1) N-acetylserotonin to sulphtoxydiacetyltryptamine via hydroxydiacetyltryptamine, and (2) melatonin to dihydromelatonin.
  
  
  CONCLUSIONS
  Severely stressful situations did not affect diurnal changes in melatonin, hydroxydiacetyltryptamine, sulphatoxydiacetyltryptamine, or N-acetylserotonin levels in urine.
authors.affiliation: Chronic Fatigue Research Center, Institute for Science of Labour, 2-8-14 Sugao, Miyamae-ku, Kawasaki 216-8501, Japan. m.minami@isl.or.jp
authors.forename: Masayasu
authors.initials: M
authors.lastname: Minami
authors.forename: Hideyo
authors.initials: H
authors.lastname: Takahashi
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sasaki
authors.forename: Shun
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sakai
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamano
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Miyake
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm; D005221:Fatigue / Q000378:metabolism / Q000652:urine; D005470:Fluorometry; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000652:urine; D025341:Principal Component Analysis; D012892:Sleep Deprivation / Q000378:metabolism* / Q000523:psychology* / Q000652:urine; D013315:Stress, Psychological; D011795:Surveys and Questionnaires; D014363:Tryptamines / Q000378:metabolism / Q000652:urine*; D055815:Young Adult
chemical_list: D014363:Tryptamines; D008550:Melatonin