Increased 8-oxo-dGTPase in the mitochondria of substantia nigral neurons in Parkinson's disease

There is growing evidence for the involvement of oxidative stress and mitoc hondrial respiratory failure in nigral neuronal death in Parkinson's diseas e (PD). We report increased immunoreactivity of 8-oxo-dGTPase (8-oxo-7, 8-d ihydrodeoxyguanosine triphosphatase [hMTH1]), an enzyme known to play an im portant role in controlling spontaneous mutagenesis, and 8-oxo-7, 8-deoxygu anosine (8-oxo-dG) in the mitochondria of the substantia nigra of 6 PD pati ents. Our results suggest that hMTH1 might be a useful marker of oxidative stress and can be used to explore the relation between such oxidative stres s and genomic instability.