[Changes in monoamine metabolites in the nucleus accumbens and locomotor activity by reserpine: an in vivo microdialysis study].

The effect of ip administration of reserpine (2 mg/kg) on the monoamine metabolites 3,4-dihydroxyphenyl acid (DOPAC), homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA) was estimated in the freely moving rat by intracerebral dialysis in the nucleus accumbens. Locomotor activity was measured simultaneously by Automex. Locomotor activity tended to increase during the first 2 hours. On the other hand, a significant reduction of locomotor activity was found during the 3rd-5th hour period of the experiment. HVA-total (conjugated + free) and 5-HIAA were elevated significantly (P less than 0.05) during the 3rd-5th and the 5th-6th hour periods, respectively. However, the difference of DOPAC between both groups did not reach statistical significance throughout the experiment. During the 3rd-5th hour of experiment, the change of behavior and HVA were inversely correlated. This might suggest that an HVA level in the dialysate is a good index of dopamine metabolism in the nucleus accumbens after reserpine treatment.