Cu/Zn superoxide dismutase activity at different ages in sporadic amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive disorder resulting fro m degeneration of motor neurons in the brain and spinal cord. Sporadic ALS (SALS) accounts for the majority of patients and the familial form (FALS) r epresents fewer than 10% of all cases. Since it was found that there are Cu /Zn superoxide dismutase (SQD1) gene mutations in 20% of FALS patients and that FALS and SALS patients show similar clinical features, it has been pos tulated that both may share a common physiopathological mechanism. We studi ed Cu/Zn SOD1 activity in cytosolic extracts of erythrocytes from 125 norma l individuals and 40 SALS patients. We found that enzyme activity does not change with age in control subjects and tends to decrease in most SALS pati ents older than 60 years. A subpopulation of five SALS patients had signifi cantly increased SOD1 activity; four of these patients over 70 years old. T here was no correlation between enzyme activity and time of onset of the di sease, or clinical forms of the illness. The variation in SOD1 activity in ageing SALS patients compared with younger patients suggests that they may undergo an oxidative disbalance contributing to the development of the dise ase. (C) 1999 Elsevier Science B.V. All rights reserved.