Selective nigral toxicity after systemic administration of 1-methyl-4-phenyl-1,2,5,6-tetrahydropyrine (MPTP) in the squirrel monkey.

1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) was administered via the intraperitoneal route to squirrel monkeys. Akinesia, rigidity and hypophonia were seen after repeated doses of 2 mg/kg. Postural tremor was present in one animal. Neuropathologic examination revealed cell loss restricted to the zona compacta of the substantia nigra. MPTP appears effective in producing an animal model for Parkinson's disease in the squirrel monkey, and may be one of the more selective neurotoxins described to date.