title: Simultaneous analysis of D- and L-serine in cerebrospinal fluid by use of HPLC.
abstract: BACKGROUND
  D-Serine is a coagonist for the glycine-binding site of the N-methyl-D-aspartate receptors and has been implicated in various neuropsychiatric functions such as learning, memory, and nociception, as well as schizophrenia and Alzheimer disease. We developed an HPLC method for D- and L-serine in cerebrospinal fluid (CSF).
  
  
  METHODS
  The dabsylated racemic serine peak, automatically collected using a previously reported HPLC separation process for CSF amino acids, was desalted and subjected to a chiral resolution HPLC step with a Sumichiral column using an ultraviolet-visible detector.
  
  
  RESULTS
  The limits of quantification (signal-to-noise ratio = 10) for D- and L-serine were 0.8 and 1.3 micromol/L, respectively. The mean imprecision values (CVs) for within-day measurements of D- and L-serine were 2.1% and 1.8%, respectively, and for between-day were 6.2% and 6.6%. Mean recovery of CSF serine (sum of D-serine + L-serine) applied to the Sumichiral column was 87%. The mean (SD) d-serine concentrations in 45 CSF samples obtained from 16 patients with chronic pain due to degenerative osteoarthritis of the knees, 16 with postherpetic neuralgia, and 13 with no pain were, respectively, 3.97 (0.44), 1.85 (0.21), and 2.72 (0.32) micromol/L.
  
  
  CONCLUSIONS
  D- and L-serine can be quantified with ultraviolet-visible detection of dabsyl derivatives. The dabsyl derivatives are stable and allow duplicate analysis of CSF samples in multisample runs.
authors.affiliation: Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Rama
authors.initials: R
authors.lastname: Sethuraman
authors.forename: Malathi G
authors.initials: MG
authors.lastname: Krishnamoorthy
authors.forename: Tat-Leang
authors.initials: TL
authors.lastname: Lee
authors.forename: Eugene Hern C
authors.initials: EH
authors.lastname: Liu
authors.forename: Siau
authors.initials: S
authors.lastname: Chiang
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishimura
authors.forename: Masato
authors.initials: M
authors.lastname: Sakai
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Minami
authors.forename: Shinro
authors.initials: S
authors.lastname: Tachibana
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D012694:Serine / Q000134:cerebrospinal fluid* / Q000737:chemistry; D013053:Spectrophotometry; D013237:Stereoisomerism; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives
chemical_list: D007202:Indicators and Reagents; D012694:Serine; C010572:4-N,N-dimethylaminoazobenzene-4'-sulfonyl chloride; D004124:p-Dimethylaminoazobenzene