Inhibition of uptake of 1-methyl-4-phenylpyridinium ion and dopamine in striatal synaptosomes by tobacco smoke components.

To determine whether the attenuation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity by tobacco smoke exposure is caused by inhibition of the neuronal uptake of 4-phenylpyridinium ion (MPP+), various tobacco components and a smoke extract were tested for inhibitory activity in striatal synaptosomes. A dimethylsulfoxide extract of tobacco smoke filtrate was found to inhibit the uptake of MPP+ and dopamine. These results suggest that inhibition of the neuronal dopamine uptake mechanism may account for the protective effects of smoke exposure on MPTP-induced neurotoxicity.