[Concentrations of monoamines and monoamine metabolites in cerebrospinal fluid determined by high-performance liquid chromatography with electrochemical detection].

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 norepinephrine (NE), as well as monoamine metabolites, in small amounts of human CSF. The first 2 ml of CSF was obtained from 61 patients (27 males and 34 females), aged from 15 to 88 years, with a variety of non-neurological diseases by lumbar puncture performed between 8:45 a.m. and 4:20 p.m. CSF was collected in the lateral decubitus position before lumbar anesthesia for surgical treatment. Samples were immediately frozen at -80 degrees C until assayed. None had any history of neurological or psychiatric illness. Concentrations in lumbar CSF were 10.9 +/- 6.0 pg/ml (mean +/- SD, n = 22) for DA, 105.8 +/- 63.6 pg/ml (n = 60) for NE, 30.5 +/- 1.6 ng/ml (n = 61) for homovanillic acid (HVA), 1.8 +/- 1.2 ng/ml (n = 46) for 3,4-dihydroxyphenylacetic acid (DOPAC), 7.7 +/- 2.1 ng/ml (n = 46) for 3-methoxy-4-hydroxyphenylglycol (MHPG) and 18.8 +/- 10.9 ng/ml (n = 61) for 5-hydroxyindoleacetic acid (5 HIAA), respectively. While 5 HIAA concentrations in lumbar CSF taken 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 measurement of individual monoamine or monoamine metabolite level in CSF, future studies should be extended to include comparisons of a mutual relationship among several monoamine metabolites.