title: [Alterations of plasma aspartic acid, glycine and asparagine levels in patients with major depressive disorder].
abstract: OBJECTIVE
  To evaluate the changes of plasma levels of the excitatory amino acid neurotransmitter aspartic acid (Asp), inhibitory neurotransmitter glycine (Gly) and asparagine (Asn) in patients with major depressive disorder (MDD).
  
  
  METHODS
  Plasma samples were collected from 15 MDD patients (9 males and 6 females, aged 32-64 y) and 14 healthy subjects (7 males and 7 females, aged 30-65 y); and also collected from 7 MDD patients (5 males and 2 females) 2 months after antidepressant treatment. The plasma levels of amino acids were determined by high performance liquid chromatography with fluorescence detection method.
  
  
  RESULTS
  Plasma Asp and Gly levels were significantly lower in MDD patients than those in controls (P<0.04). There were positive correlations between plasma levels of Gly and Asp, and between Gly and Asn (P<0.005) in the control group; while in MDD patients, a significant positive correlation was found only between plasma levels of Gly and of Asp (P<0.001). MDD patients did not show significant changes in plasma Asp, Asn and Gly levels after antidepressant treatment compared to those before treatment.
  
  
  CONCLUSIONS
  The reduced plasma Asp and Gly levels may serve as a clinical biomarker for MDD.
authors.affiliation: Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China.
authors.forename: Xin-yan
authors.initials: XY
authors.lastname: Fu
authors.forename: Yun-rong
authors.initials: YR
authors.lastname: Lu
authors.forename: Juan-li
authors.initials: JL
authors.lastname: Wu
authors.forename: Xue-yan
authors.initials: XY
authors.lastname: Wu
authors.forename: Ai-min
authors.initials: AM
authors.lastname: Bao
mesh_terms: D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use; D001216:Asparagine / Q000097:blood*; D001224:Aspartic Acid / Q000097:blood*; D003865:Major Depressive Disorder / Q000097:blood* / Q000188:drug therapy; D005260:Female; D005998:Glycine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000928:Antidepressive Agents; D001224:Aspartic Acid; D001216:Asparagine; D005998:Glycine