Current concepts: II. Measurement of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in discrete brain nuclei using reverse phase liquid chromatography with electrochemical detection

A rapid and sensitive method has been outlined for the measurement of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) utilizing a weak cation-exchange resin and liquid chromatography with electrochemical detection. The sensitivity of the procedure allows measurement of the amine in punches of rat substantia nigra even after local injection of the neurotoxin 5,7-dihydroxytryptamine. Increases in 5-HT and decreases in 5-HIAA concentrations after pargyline, and selective increases in 5-HIAA concentrations after probenecid were detected in selected brain regions (nucleus accumbens, anterior striatum, substantia nigra). Thus, this procedure is sensitive enough to estimate 5-HT turnover in discrete nuclei of the rat brain.