Effects of acute and chronic administration of phencyclidine on the levels of dopamine and metabolites in discrete brain areas of mouse

The effects of phencyclidine (PCP) on the levels of dopamine (DA) and metabolites in discrete brain areas of mouse were investigated. In acute experiment, PCP significantly decreased the level of DOPAC but increased that of HVA in the striatum 60 min after the administration. PCP also increased the HVA level in the midbrain and cortex in a dose dependent fashion 60 min after the injection. On the other hand, chronic treatment of PCP produced a significant increase of the striatal DA level but 24 and 48 hr withdrawal from PCP decreased the DOPAC levels in the striatum and cortex. In the midbrain, the DA level was decreased but HVA level was significantly increased in the chronic PCP treated group. However, the increment of HVA levels in the acute experiment was no longer observed in the striatum and cortex. These results suggest that the pharmacological actions of PCP and tolerance development to PCP may be related to the functional changes of dopaminergic neuronal activity.