電極式検出器付高速液体クロマトグラフィー法による髄液中モノアミンとその代謝物濃度の検討

CONCENTRATIONS OF MONOAMINES AND MONOAMINE METABOLITES IN CEREBROSPINAL FLUID DETERMINED BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

　抄録　電極式検出器付高速液体クロマトグラフィー法による髄液中モノアミンとモノアミン代謝物の測定法を確立した。本法は操作が簡単で，しかも高感度であることから，少量の髄液を用いてのNEやDAの測定も可能であることがわかつた。中枢神経系疾患以外の手術患者での腰部髄液中各物質濃度はNE 105.8±63.6 pg／ml （mean±SD），　DA 10.9±6.0 pg／ml, HVA 30.5±1.6 ng／ml, DOPAC 1.8±1.2 ng／ml，MHPG 7.7±2.1ng／ml．5HIAA 18.8±10.9ng／mlであった。髄液採取時刻との関係では，5HIAAは日中に順次低下する傾向がみられ，MHPGは午後に採取された髄液で有意に高値を示した。各物質濃度には性差は認められなかつた。HVAとDOPACは加齢とともに低下する傾向がみられたが，他のものでは年齢との相関を見出せなかつた。各物質濃度の関係では，HVA, MHPGおよび5HIAAの三者間で有意の相関関係が認められた。以上の成績から，各中枢神経疾患患者の髄液中モノアミンとその代謝物濃度を比較する場合には，髄液採取条件を一定にすること，および各物質濃度の変化を相互のバランスという面から検討することが重要であると考えられた。

Using reversed-phase high-performance liquid chromatography with an electrochemical detection, I have developed a sensitive technique to measure monoamines and their metabolites in cerebrospinal fluid (CSF). The present method has been shown to offer simplicity and high sensitivity for the determination of dopamine (DA) and norepineph-rine (NE), as well as monoamine metabolites, in small amounts of human CSF.

The first 2 ml of CSF was obtained from 61 pa-tients (27 males and 34 females), aged from 15 to 88 years, with a variety of non-neurological dise-ases by lumbar puncture performed between 8: 45 a. m. and 4:20 p. m. CSF was collected in the lateral decubitus position before lumbar anesthe-sia for surgical treatment. Samples were immedia-tely frozen at-80℃ until assayed. None had any history of neurological or psychiatric illness.

Concentrations in lumbar CSF were 10.9±6.0 pg/m/(mean±LSD, n=22) for DA, 105.8±63.6pg/ ml (n=60) for NE, 30.5±1.6ng/ml (n=61) for homovanillic acid (HVA), 1. 8±1.2ng/ml (n=46) for 3,4-dihydroxyphenylacetic acid (DOPAC), 7.7±2.1 ng/m/(n=46) for 3-methoxy-4-hydroxyphe-nylglycol (MHPG) and 18. 8±10.9 ng/m/ (n=61) for 5-hydroxyindoleacetic acid ( 5 HIAA), respectively. While 5 HIAA concentrations in lumbar CSF ta-ken in the afternoon tended to be lower than those in the morning, MHPG in the afternoon was significantly higher than that in the morning. There were no sex differences in the concentrations of monoamines and their metabolites examined. There was a tendency for the concentrations of HVA and DOPAC to be lower in older subjects. A significant correlation was found among HVA, 5 HIAA and MHPG concentrations in lumbar CSF.

The present study suggests that a standardized condition for collecting CSF should be employed to compare the concentrations of monoamines and their metabolites across central nervous system disorders. Furthermore, in addition to the mea-surement of individual monoamine or monoamine metabolite level in CSF, future studies should be extended to include comparisons of a mutual re-letionshin among several monoamine metabolites.