The toxicity of mptp (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) to Periplaneta americana l. and its effects on dopamine in the cerebral ganglia

MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and MPP⁺ (1-methyl-4-phenylpyridinium ion) are potent dopaminergic neurotoxins in mammals. The mammalian toxicity of MPTP depends on its conversion, by monoamine oxidase, to MPP⁺. MPTP is toxic to cockroaches (LD₅₀ 720 μg gm^?1) and the results suggest that MPTP toxicity depends on monoamine oxidase activity at a site outside the nervous system. MPTP depletes dopamine from cockroach cerebral ganglia and MPP⁺ inhibits cockroach mitochondrial respiration. While the biochemistry of MPTP toxicity appears to be the same as in mammals it seems that insects are unable to detoxify MPTP before its action has fatal consequences outside the nervous system.