Superoxide dismutases, glutathione peroxidase, and catalase in neuromuscular disease

Studies in experimental muscular dystrophy indicate a possible role for anomalous redox metabolism in the genesis of these disorders, prompting a retrospective review of changes in redox-active enzymes in Duchenne muscular dystrophy (DMD). Both manganous and copper-zinc superoxide dismutase (Mn and CuZn SOD) content and glutathione peroxidase and catalase activities were measured in muscle biopsy specimens taken from normal individuals and from patients with Duchenne muscular dystrophy and other neuromuscular diseases. Muscle from patients with Duchenne dystrophy differed from the norm in that both Mn SOD and CuZn SOD were decreased and glutathione peroxidase was increased. This profile differed from that in anterior horn cell diseases in that CuZn SOD was not decreased in these disorders and from polymyositis, where CuZn SOD was decreased without an increase in glutathione peroxidase. Thus, there appears to be disease-specific changes in these enzymes in DMD. These data support the concept that changes in redox-active enzymes may be associated with the genesis of DMD.