ABSTRACT
The involvement of the superoxide radical in an experimental system is usually ascertained indirectly by the demonstration of an effect of superoxide dismutase (SOD). For example, it has been demonstrated that the autoxidation of 6-hydroxydopamine (6-OHDA) is inhibited by SOD. 1 This inhibitory effect of SOD suggests that the superoxide radical is generated during this autoxidation and, further, that the superoxide radical promotes the rate of autoxidation of 6-OHDA. However, before one concludes definitively about the involvement of the superoxide radical, one must demonstrate that the observed effect of SOD is due to its enzymatic activity, i.e., its removal of the superoxide radical. One must therefore be able to demonstrate that an enzymatically inactive SOD has no effect in the experimental system.
