NEUROAMINE RELATED-COMPOUNDS IN THE CSF OF HYDROCEPHALIC RABBITS

THE effects of neonatal hydrocephalus on the levels of tyrosine, trypt ophan, 5-hydroxyindoleacetic acid (5-HIAA), and homovanillic acid (HVA ) in CSF were determined by high-performance liquid chromatography (HP LC) with fluorometric detection in normal and chronically hydrocephali c rabbits. The hydrocephalic rabbits showed a highly significant incre ase in both the serotonin metabolite 5-HIAA and the dopamine metabolit e HVA. There were no significant effects of the hydrocephalus on eithe r tyrosine or tryptophan levels. There was a significant positive corr elation between the intracranial pressure (ICP) and the increase in 5- HIAA and HVA, but not with the two precursor amino acids. There was a significant decrease in these amino acid precursors with age in both g roups. A trend towards higher levels of 5-HIAA and HVA in older rabbit s was also evident, however this change was not to the degree found in the hydrocephalics. These data indicate that increased ICP affects th e mechanism of removal of 5-HIAA and HVA from the cerebrospinal fluid.