Assessment of cerebrospinal fluid levels of dopamine metabolites by gas chromatography.

The acid metabolites of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined in lumbar cerebrospinal fluid (CSF) by a new procedure. After gas chromatographic separation, the pentafluoroprionyl 2,2,3,3,3-pentafluoro-1-propionyl esters of DOPAC and HVA were analyzed by electron capture detection. Normal HVA levels were quantitated in as little as 0.1 ml CSF. No significant amounts of DOPAC (less than 1 ng/ml) were found in any of the drug-free samples analyzed. Levels of DOPAC increased only marginally in the CSF of patients receiving acute or chronic doses of L-Dopa. Baseline HVA levels ranged from 4.5--50 ng/ml with a mean value of 23 ng/ml. These studies demonstrate that HVA is the major dopamine metabolite in human CSF.