Cell death in Parkinson's disease.

The cause of neuronal cell death in Parkinson's disease is still an enigma. However, recent results obtained by analyses of postmortem brain suggest that a mitochondria-dependent apoptotic signal was activated. The involvement of dopamine-derived endogenous neurotoxin in the pathogenesis of PD was also indicated. N-Methyl( R)salsolinol was proved to be selectively toxic to dopamine neurons and its level increased in parkinsonian CSF. The enzyme which determines the level of N-methyl( R)salsolinol, ( R)salsolinol N-methyltransferase, was found increased in the lymphocytes prepared from PD patients. The mechanism of dopamine cell death by N-methyl( R)salsolinol was studied in vitro. N-Methyl( R)salsolinol induced apoptosis in human dopaminergic neuroblastoma cells. It was suggested that in the mitochondria there is a molecule which interacts with N-methyl( R)salsolinol and initiates an apoptotic signal.