title: Simultaneous determination of tyrosine, tryptophan and 5-hydroxytryptamine in serum of MDD patients by high performance liquid chromatography with fluorescence detection.
abstract: BACKGROUND
  Tyrosine (Tyr), Tryptophan (Trp) and 5-hydroxytryptamine (5-HT) are important amino acids in vivo and have been hypothesized to be involved in many mental disorders. We developed a rapid and sensitive HPLC method for simultaneous measurement of serum Tyr, Trp and 5-HT and explored the clinical significances of Tyr, Trp and 5-HT and the 5-HT/Trp ratio for patients with major depressive disorder (MDD) disease.
  
  
  METHODS
  Serum samples were deproteinized by 5% perchloric acid and separated on an Atlantis C18 column (4.6 × 150 mm, 5 μm) with the mobile phase consisting of 0.1 mol/l KH(2)PO(4) and methanol (85:15, V/V).The eluates were monitored by the fluorescence detection with programmed wavelength.
  
  
  RESULTS
  Analysis was achieved in <12.0 min. The limits of quantification were 0.014, 0.005, and 0.024 μmol/l for Tyr, Trp and 5-HT, respectively. Reproducibility and recovery were satisfactory. Tyr, Trp and 5-HT and the 5-HT/Trp ratio were significantly decreased in patients with MDD.
  
  
  CONCLUSIONS
  In diseases, like MDD, Tyr, Trp and 5-HT play an important role. This method can potentially be applied as prognostic or diagnostic tool or even to follow the evolution of the illness or of the treatment.
authors.affiliation: Department of Clinical Laboratory, The Second Xiangya Hospital, Central South University, Changsha, 410011 Hunan, PR China.
authors.forename: Mu
authors.initials: M
authors.lastname: Sa
authors.forename: Li
authors.initials: L
authors.lastname: Ying
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Tang
authors.forename: Le-Dong
authors.initials: LD
authors.lastname: Xiao
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Ren
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000737:chemistry; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003865:Major Depressive Disorder / Q000097:blood*; D005260:Female; D005453:Fluorescence; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012701:Serotonin / Q000097:blood*; D013997:Time Factors; D014364:Tryptophan / Q000097:blood*; D014443:Tyrosine / Q000097:blood*; D055815:Young Adult
chemical_list: D001798:Blood Proteins; D012701:Serotonin; D014443:Tyrosine; D014364:Tryptophan