Unilateral deficits induced in rats by MPP+ are markedly reduced by an N-terminal peptide fragment of dopamine-releasing protein.

Dopamine-releasing protein (DARP) is a novel factor involved in the function and development of catecholaminergic systems. To test whether a peptide synthesized from the N-terminus of DARP (DARP-36aa) ameliorates deficits in nigrostriatal dopamine, rats were unilaterally lesioned with MPP+, 1 day before administration of DARP-36aa began. Striatal delivery of 1 microgram DARPP-36aa daily for 10 days elevated striatal dopamine (P < 0.01) and reduced amphetamine-induced rotations (P < 0.05) relative to controls, both indicating the protection or restoration of dopaminergic function.