RILUZOLE PREVENTS MPTP-INDUCED PARKINSONISM IN THE RHESUS-MONKEY - A PILOT-STUDY

Previous studies have shown that riluzole (2-amino-6-trifluoromethoxy- benzothiazole), a drug which interferes with glutamate neurotransmissi on, has a neuroprotective action in rodent models of global and focal cerebral ischemia. In this pilot study, the protective and palliative effects of riluzole have been examined using an animal model of Parkin son's disease. Two monkeys were rendered hemiparkinsonian by one intra carotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPT P), and motor signs were evaluated using clinical examination and elec tromyographic recordings. When riluzole (4 mg/kg) was administered bef ore the injection of MPTP, parkinsonian motor symptoms, in particular bradykinesia and rigidity, were absent. When injected daily in one mon key which presented stable motor symptoms, bradykinesia and rigidity w ere significantly reduced. Riluzole pretreatment induced a persistent increase in dopamine turnover when compared to MPTP alone. Thus, a pos sible neuroprotection and a facilitation of dopamine release may expla in the behavioural effects reported with riluzole treatment. These pre liminary results suggest that riluzole could possess neuroprotective a nd palliative effects in a primate model of Parkinson's disease.