Simultaneous analysis of D- and L-serine in cerebrospinal fluid by use of HPLC.
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.
Sethuraman
Rama
R
Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Krishnamoorthy
Malathi G
MG
Lee
Tat-Leang
TL
Liu
Eugene Hern C
EH
Chiang
Siau
S
Nishimura
Wataru
W
Sakai
Masato
M
Minami
Toshiaki
T
Tachibana
Shinro
S
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
D007202:Indicators and Reagents; D012694:Serine; C010572:4-N,N-dimethylaminoazobenzene-4'-sulfonyl chloride; D004124:p-Dimethylaminoazobenzene