The gold standard
therapy for
Parkinson's disease (PD),
L-3,4-dihydroxyphenylalanine (
L-DOPA), induces
dyskinesias in the majority of patients after years of treatment.
Ethanolamine plasmalogens (PlsEtn) play critical roles in membrane structure mediated functions and as a storage depot of
polyunsaturated fatty acids such as
docosahexaenoic acid. We previously showed that a PlsEtn precursor
PPI-1011 reduced already established
L-DOPA-induced
dyskinesias (LID) in
1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (
MPTP) lesioned monkeys as a PD model. We hypothesize that development of LID can be prevented with a
PPI-1011 treatment in de novo
MPTP-lesioned monkeys.
MPTP-lesioned monkeys were treated once daily for 28days with either
L-DOPA or L-DOPA+PPI-1011 (25mg/kg). The antiparkinsonian effect of
L-DOPA was maintained throughout the treatment period in
MPTP-lesioned monkeys treated with
L-DOPA alone and L-DOPA+PPI-1011. Over the 28days of treatment, the mean
dyskinesia score increased in
L-DOPA-treated monkeys whereas this increase was significantly less in the L-DOPA+PPI-1011 group. This was followed by a washout period of 2 weeks of both experimental groups without treatment. Then both groups were administered once during week 7 and twice during week 8 with
L-DOPA with behavioral measures recorded on treatment days.
MPTP monkeys of both experimental groups administered
L-DOPA in experimental week 7 showed reduced LID. During week 8, the
L-DOPA group showed increased LID whereas LID remained low in the group previously treated with L-DOPA+PPI-1011. The present results suggest that
PPI-1011 can prevent/delay the development of LID while maintaining the antiparkinsonian activity of
L-DOPA.