Central nervous system biogenic amine metabolism was studied in 35 children suffering from autism, atypical development, epilespy, and movement disorders. After oral administration of probenecid, a membrane blocking compound, a cerebrospinal fluid (CSF) sample was obtained for assay of homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5HIAA), and probenecid. The concentrations of HVA and 5HIAA in the CSF are thought to reflect the rate of formation in the brain of their parent amines, dopamine and serotonin, respectively.
There are statistically significant differences in CSF HVA and 5HIAA levels between the psychotic and epileptic children. The HVA and 5HIAA are significantly correlated with each other. Each of these acid metabolites covaries with the CSF levels of probenecid and interpretation of the significance of CSF HVA and 5HIAA requires simultaneous measurement of probenecid concentration.
Cohen DJ, Shaywitz BA, Johnson WT, Bowers M. Biogenic Amines in Autistic and Atypical ChildrenCerebrospinal Fluid Measures of Homovanillic Acid and 5-Hydroxyindoleacetic Acid. Arch Gen Psychiatry. 1974;31(6):845-853. doi:10.1001/archpsyc.1974.01760180085011