Journal of the Neurological Sciences 162 (1999) 34–37 Cu / Zn superoxide dismutase activity at different ages in sporadic amyotrophic lateral sclerosis a, a a b b * ´ Monica L. Fiszman , Laura N. Borodinsky , Karina C. Ricart , Olga P. Sanz , Roberto E.P. Sica a ´ ´ Laboratorio de Neurociencias, Centro de Investigaciones Medicas Albert Einstein, Fundacion CIMAE, Luis Viale 2831 (1416), Buenos Aires, Argentina b ´ ´ ´ Division Neurologıa, Hospital Ramos Mejıa, Universidad de Buenos Aires, Buenos Aires, Argentina Received 8 July 1998; accepted 21 August 1998 Abstract Amyotrophic lateral sclerosis (ALS) is a progressive disorder resulting from degeneration of motor neurons in the brain and spinal cord. Sporadic ALS (SALS) accounts for the majority of patients and the familial form (FALS) represents fewer than 10% of all cases. Since it was found that there are Cu / Zn superoxide dismutase (SOD1) gene mutations in 20% of FALS patients and that FALS and SALS patients show similar clinical features, it has been postulated that both may share a common physiopathological mechanism. We studied Cu/Zn SOD1 activity in cytosolic extracts of erythrocytes from 125 normal individuals and 40 SALS patients. We found that enzyme five SALS patients had significantly increased SOD1 activity; four of these patients over 70 years old. There was no correlation between enzyme activity and time of onset of the disease, 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 disease.  1999 Elsevier Science B.V. All rights reserved. Keywords: SALS; SOD1 activity; Ageing; Red blood cells 1. Introduction the superoxide dismutase (SOD) gene has given impetus to research on the role of oxidative stress in the pathogenesis Amyotrophic lateral sclerosis (ALS) is a progressive of familial ALS (FALS) [19,25]. The role of SOD neurodegenerative disease in which both upper and lower anomalies in its pathogenesis is also supported by evidence motoneurons are affected. It occurs in both sporadic and from transgenic mice with mutated versions of the enzyme familial forms; about 10% of ALS cases are familial with [13,22]. The manifestations of the disease are delayed by an autosomal dominant trait and 20% of these have the administration of SOD or glutamate blockers [12]. mutations in the antioxidant enzyme Cu,Zn superoxide Several studies have shown that SOD1 mutations provide a dismutase (SOD1). SOD catalyses the dismutation of prooxidant activity to the enzyme, while superoxide dis- superoxide radical into hydrogen peroxide and molecular mutase activity remains unchanged [28,29]. Oxidative oxygen. SOD1 mutations in sporadic ALS (SALS) are not stress has also been thought to be a contributing factor in common, and only four over 155 cases were reported by the pathogenesis of the sporadic forms of the disease as Jackson et al. [15]. The discovery of mutations affecting well, because both groups of patients show identical clinical features. Moreover, abnormal oxidative damage to proteins and lipids has been demonstrated in post-mortem samples from both the cortex and spinal cord of FALS and * SALS patients [6,11]. Increased 3-nitrotyrosine, a rela- Corresponding author. Tel.: 154-1-582-7599; fax: 154-1-582-7879; e-mail: fiszman@connmed.com.ar tively specific marker for oxidative damage mediated by 0022-510X / 99 / $ – see front matter  1999 Elsevier Science B.V. All rights reserved. PII: S0022-510X(98)00272-X