Intra- and Inter-individual Relationships between Central and Peripheral Serotonergic Activity in Humans:: A Serial Cerebrospinal Fluid Sampling Study
Data are lacking concerning the longitudinal covariability and cross-sectional balance between central and peripheral 5-HIAA concentrations in humans and on the possible associations between tobacco smoking or post-traumatic stress disorder (PTSD) and CSF and plasma 5-HIAA concentrations. Using serial cerebrospinal fluid (CSF) and blood sampling, we determined the concentrations of 5-HIAA in CSF and plasma over 6 h, and examined their relationships in healthy volunteers and patients with PTSD—both smokers and nonsmokers. Patients with PTSD and healthy volunteers had very similar CSF 5-HIAA concentrations. Significant and positive correlations between CSF and plasma 5-HIAA levels were observed within individuals, but this CNS-peripheral 5-HIAA relationship was significantly reduced in smokers (nonsmokers: mean r = 0.559 ± 0.072; smokers: mean r = 0.329 ± 0.064 p < 0.038). No significant cross-sectional, interindividual correlation of mean CSF and mean plasma 5-HIAA was seen (r = 0.094). These data show that changes in CSF 5-HIAA levels within an individual over time are largely reflected in plasma 5-HIAA, albeit significantly less so in smokers. The present results therefore suggest that clinically, longitudinal determination of plasma 5-HIAA concentrations within an individual patient can be used to make inferences about relative changes in integrated CSF 5-HIAA concentrations. However, plasma 5-HIAA concentrations provide no significant information about absolute levels of the serotonin metabolite in the CSF.
Strawn, J. R.,
Ekhator, N. N.,
Anthenelli, R. M.,
Baker, D. G.,
Hill, K. K.,
& Geracioti, T. D.
(2002). Intra- and Inter-individual Relationships between Central and Peripheral Serotonergic Activity in Humans:: A Serial Cerebrospinal Fluid Sampling Study. Life Sciences, 71 (10), 1219-1225.