The synthetic ceramide analog l-PDMP partially protects striatal dopamine levels but does not promote dopamine neuron survival in murine models of parkinsonism

A number of previous studies have demonstrated a positive effect of exogenously administered monosialoganglioside GM1 on striatal dopamine (DA) levels and DA neuron survival in animal models of parkinsonism. However, due to low bioavailability of peripherally administered GM1, the present study investigated the neuroprotective/neurorestorative potential of enhancing endogenous GM1 biosynthesis by administration of the synthetic ceramide analog l-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (l-PDMP) in two mouse models of Parkinsonism produced by acute or subacute 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration. l-PDMP treatment caused an increase in brain GM1 levels in both Parkinson models and resulted in a partial sparing of striatal DA levels in the subacute MPTP model but not in the acute MPTP model. l-PDMP treatment had no effect on DA neuron survival in either model. These data suggest that the administration of l-PDMP as a means to enhance endogenous brain GM1 levels may hold limited promise as a potential neuroprotective or neurorestorative therapeutic strategy for Parkinson's disease.