Superoxide dismutase activity in early and advanced Parkinson's disease

Superoxide dismutase (SOD) is an enzyme system that is implicated in the oxidant stress model of Parkinson's disease (PD) pathogenesis. This study was designed to assess SOD activity in whole blood and red blood cells of PD patients in early and advanced stages of the disease. Fifteen PD patients in stage I and II (group A) and 15 in stage III and IV (group B) as well as 15 normal controls were included in the study. SOD activity was assessed in whole blood and red blood cells. Group B patients showed a statistically significant decrease of SOD activity in whole blood and in red blood cells. A negative correlation between SOD activity and duration of the disease was observed, while there was no relationship between L-Dopa treatment and SOD activity. Our results indicate that a defect in SOD activity develops over time in PD. Whether this is a later manifestation of antioxidant mechanism deterioration or simply an epiphenomenon remains unclear.