Differential pulse voltammetry in vivo--evidence that uric acid contributes to the indole oxidation peak.
Crespi F., Sharp T., Maidment N., Marsden C.
Previous studies using differential pulse voltammetry have shown that indoleamines contribute to the oxidation peak at +280-300 mV (peak 3) measured in the rat striatum in vivo using carbon fibre electrodes. In this study, using similar techniques, it is shown that 5-hydroxyindoleacetic acid and uric acid oxidize at a similar potential (+270-290 mV) in vitro. Additionally, by microinfusing uric acid or its metabolizing enzyme uricase, it is shown that uric acid oxidation contributes to about 30% of the height of peak 3 measured in the rat striatum in vivo. These results indicate that care needs to be taken in interpreting changes in the height of the in vivo peak 3 since it is not solely due to the oxidation of brain indoleamines.