Receptor-activity modifying protein 1 expression is increased in the striatum following repeated L-DOPA administration in a 6-hydroxydopamine lesioned rat model of Parkinson's disease.

Abnormalities in signaling by G-protein coupled receptors (GPCRs) within the striatum are involved in the pathophysiology of Parkinson's disease (PD) and L-DOPA induced dyskinesia (LID). Receptor activity modifying proteins (RAMPs) are single transmembrane accessory proteins crucial for both trafficking and defining the phenotype of GPCRs. In the CNS, RAMP1 mRNA is predominantly expressed in striatum, cortex, and olfactory tubercles. In the present study, expression of RAMP1 mRNA is increased in the striatum (68-77%), following repeated L-DOPA administration, in the 6-hydroxydopamine-lesioned rat. These data are the first to describe regulation of RAMP1 expression in the CNS and suggest that changes in RAMP1 activity are involved in the pathophysiology of LID.