Different neurotransmitter metabolite concentrations in CSF samples from inpatient and outpatient normal volunteers

Abstract

Cerebrospinal fluid concentrations of the neurotransmitter metabolites 5-hydroxyindoleacetic acid (5HIAA), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were compared in two groups of healthy volunteer subjects. One group (outpatient) was composed of 27 subjects who were transported to the outpatient clinic on the day of the lumbar puncture (LP). The other group (inpatient) was composed of 10 subjects who were admitted to the NIMH Research Ward on the evening prior to the LP. After statistical adjustment for age, height, sex and season in which LP was performed the inpatient group had significantly higher concentrations of both 5HIAA and HVA (P less than 0.005 and P less than 0.05, respectively) than the outpatient group. The difference in DOPAC concentration approached significance (P = 0.056), but there was no difference in MHPG concentration between the groups. This result indicates the need for strict control of environment in studies of CSF monoamines and their metabolites.

Neurotransmitter markers in the cerebrospinal fluid of normal subjects effects of aging and other confounding factors

“…However, in more recent studies, similarly to the present study, after having evaluated normal subjects strictly, Ballenger et al (1983) and Guthrie et al (1986) found no significant correlations between age and monoamine metabolite concentrations. Our results agree with their findings, however, the number of subjects in our oldest group is relatively small.…”

“…Similarly, in the present study, HVA concentrations were higher during the dark period of the year as compared to the light period, while 5 HIAA concentrations showed no seasonal variation. Further, Guthrie et al (1986) did not observe any seasonal changes in the CSF for HVA and 5 HIAA in normal subjects. The CSF levels of DBH in our study were significantly lower in the light period than in the dark period of the year in accordance with findings of Wirz-Justice and coworkers (1979).…”

“…Because peripheral MHPG formation reflects to CSF (Growdon and Gorkin, 1983;Kopin et al, 1983;Guthrie et al, 1986), the increased metabolic activity of peripheral noradrenergic neurons might be one cause of the age related elevation of MHPG in the CSF. On the other hand, the elevated levels of MHPG in aging may indicate increased turnover of monoamines or impaired uptake mechanism of the neurotransmitter in the brain.…”

“…There are several confounding factors to be taken into account in the interpretation of CSF studies such as circadian, physical and psychic state, diet, possible gradients of CSF, height and weight of the subject. Therefore, in this study, we attempted to standardize the collection of the samples in order to minimize the effects of confounding factors by using low monoamine diet, bed rest, the same time during the day and the lying positions to tap the CSF sample from the subject (Post et al, 1973;Banki et al, 1977;Guthrie et al, 1986;Reinikainen and Riekkinen, 1990).…”

CSF‐amine metabolites in depression, dementia and in controls

“…Although some studies seem to indicate that depression, suicidal behaviour, anxiety and insomnia are related to low 5-HIAA and HVA in CSF, the results reported on CSF-concentrations of the three metabolites have often been inconsistent as described in a review by Post et al (1). This discrepancy between the results obtained may partly be explained by differing variables such as age, sex, body height, time of the year for investigation (2, 3), patient status (in-or outpatients) (4) and the size of the cerebral ventricular system (5), which apparently influence the concentrations measured in the ventricles.…”