Determination of nanogram amounts of homovanillic acid in the central nervous system with a rapid semiautomated fluorometric method

Abstract

A semiautomated fluorometric assay technique for homovanillic acid (HVA), a metabolite of dopamine, is described. The method is based on a rapid manually performed isolation of HVA on small columns of Sephadex G 10 and an automated fluorometric detection method (continous flow). The method is highly sensitive: 2 ng HVA/ml can be reproducibly determined. The specificity of the method was confirmed by the effects of drugs on the HVA levels in the rat brain and by the distribution of HVA throughout the central nervous system: detectable levels of HVA were only found in the corpus striatum; nucleus accumbens and tuberculum olfactorius. The method is rapid (80–120 samples/day), reproducible (recoveries 80–95%) and can be applied to both brain tissue and cerebrospinal fluid.