[Effect of low-dose sulpiride on dopamine metabolism in rat nucleus accumbens and locomotor activity: studies with intracerebral dialysis].

: Changes in the concentration of dopamine (DA) and its metabolites, 3, 4-dihydroxyphenyl-acetic acid (DOPAC) and homovanillic acid (HVA), were determined sequentially in freely moving rats by using a brain dialysis method. The purpose of this study was to investigate the relationship between changes in the dopamine metabolism in the nucleus accumbens and locomotor activities following low-dose (5 mg/kg) sulpiride administration. The DA content in the dialysis fluid rose significantly 4 to 6 h after sulpiride administration. The DOPAC content rose significantly 6 h after sulpiride administration. The HVA content did not show a significant change. A slight increase of locomotor activity was found, but it was not statistically significant. The elevation of DA release in nucleus accumbens by sulpiride might relate to the clinical efficacy of low-dose administration of this drug for mood disorders.