Effects of benzamide derivatives on dopamine release from striatal slices of rats.

The effects of the benzamide derivatives, (-)-sulpiride, sultopride and nemonapride, on spontaneous and electrically evoked dopamine (DA) release from striatal slices of rats were investigated. Nemonapride at concentrations of 100 nM or higher caused a dose-dependent increase in spontaneous DA release from the slices. (-)-Sulpiride and sultopride had little effect on spontaneous DA release. The electrically evoked DA release was enhanced by (-)-sulpiride at concentrations of 100 nM or higher in the superfusate and reduced by nemonapride at 100 nM or higher. Sultopride caused a small increase in the evoked release of DA. The different activities of these drugs on DA release may account for the different clinical results they produce.