The induction of Parkinson's disease (PD) in senescence-accelerated mice (SAMP8) by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and the effects of dimethylsulfoniopropionate (DMSP) on induced PD model mice of SAMP8 were investigated for 5 wk. After many trials, the tail suspension test determining the PD symptoms indicated that an appropriate amount of MPTP clearly raises the SAMP8 mice to the PD-model mice. Moreover, DMSP administration to the PD-SAM model mice proved to completely reduce the PD symptoms in the mice and to accumulate large amounts of norepinephrine, dopamine and dioxyphenylacetate in the mouse brains without cerebellums. These results suggest that catecholamines accumulated in large quantities by the supplementation of DMSP to the double-diseased mice, PD-SAMP8 model mice, completely ameliorated the PD symptoms in these model mice.