Age related changes in anti-oxidative enzymes in cardiomyopathic hamster hearts

Membrane abnormalities and a shortened life span are closely associated with the progressive cardiomyopathy of dystrophic hamsters. In the present work we investigate whether this membrane damage is associated with changes in the primary membrane defences (the anti-oxidative enzymes). We measured the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH.Px), and catalase (CAT) in hearts of normal and cardiomyopathic (CHF 147) hamsters, aged 17 days to 12 months. In normal hearts all the enzyme activities follow a U-shaped curve: unweaned animals have 20-40% higher enzyme activities and 11-month-old hamsters 50-160% higher activities than adolescent or adult hamster hearts. Changes in this age-related pattern of enzyme activities are seen in dystrophic hearts in all but the 17-20-day-old animals. At 30 days of age and older, GSH.Px activities are decreased and SOD and CAT activities increased in cardiomyopathic hamsters compared to normal animals. SOD, while elevated, seems less affected than GSH.Px and CAT as the disease progresses. The changes in both absolute activities and ratio of activities of the anti-oxidative enzymes parallel the changes in the cardiomyopathic pathology. This work supports the view that the progressive cardiomyopathy of CHF 147 hamsters may be associated with changes in primary membrane defenses.