Mitochondrial matters in Parkinson disease: introduction.

Individuals with Parkinson disease (PD) are encountered frequently and have progressively severe neurologic changes. The central nervous system changes involve dopaminergic neurons in the basal ganglia and substantia nigra. Although usually sporadic, rare forms of PD are familial and the responsible genes have been identified. These genes affect mitochondrial function and can be studied in animals. Brains of affected animals reveal consequences of reactive oxygen species (ROS)--quinones, dopamine oxidation products, tyrosine nitration, lipid peroxidation and amino-aldehyde adducts. The three genes are important for maintaining physical and functional mitochondrial integrity. The cumulative effects of mitochondrial dysfunction, particularly those mediated by ROS, ultimately lead to at least some of the clinical and pathologic changes of PD.