Dopamine metabolites and catalepsy after lithium and haloperidol.

Lithium administered in chow produced a small increase in DA metabolites (DOPAC and HVA) in rat caudate but not cortex and augmented the increase in DA metabolites in both regions produced by haloperidol administration for 2 days. Given for 10 days with haloperidol, lithium attenuated the tolerance to an increase in DA metabolites in caudate. When administered with haloperidol for 22 days, lithium prevented the tolerance to catalepsy produced by daily administration of haloperidol alone. Lithium can augment and prolong the increase in regional DA metabolites and extend the duration of catalepsy produced by chronic haloperidol.