Neurobehavioral protection by single dose l-deprenyl against MPTP-induced parkinsonism in common marmosets

Objective Establishment of preclinical method evaluating behavioral protective actions of drugs for Parkinsons disease was attempted by using l-deprenyl (DEP) as a reference drug in MPTP-treated common marmosets. Methods Fifteen marmosets received MPTP at 2 mg/kg, subcutaneously (s.c.) per day for 3 consecutive days. To these marmosets, intragastric (i.g.) administration of DEP at 10 mg/kg was pretreated 2 hrs before each MPTP administration in DEP3 group and pretreated only in the 1st MPTP administration day in DEP1 group. As a control, distilled water (DW) was pretreated before each MPTP administration (n=5 for each of 3 groups).Results In DW group, decreased daily activity counts and increased dysfunction scores were persistently observed for 3 weeks after MPTP. In DEP groups, the similar changes of both levels to those in DW group were temporally observed after MPTP for several days and then the values recovered to the pre-MPTP levels. The results of autoradiography performed after above behavioral observations indicated that markedly lower bindings of [11C]PE2I (ligand for dopamine transporters) were observed at the striatum of DW group marmoset as compared with the striatum of additionally prepared MPTP-free marmoset (n=5). The bindings in DEP groups were almost the same as in the MPTP-free marmoset brains. Conclusion The present preclinical methods using continuous recording of activity of marmosets in their living cages and autoradiography using dopmamine transporter ligand might be sensitive for detecting protective actions of drugs for Parkinsons disease