ALTERATION OF SUPEROXIDE-DISMUTASE ACTIVITY IN THE ANTERIOR HORN IN MOTONEURON DISEASE PATIENTS

Studies on anterior horn dissected from MND patients have demonstrated that MnSOD activity is increased when expressed as a percentage of to tal SOD activity when compared to controls. Total SOD activity (mean /- SD) in controls = 414 +/- 105 U mg(-1) tissue and in MND patients = 373 +/- 115 U mg(-1) tissue, whereas CuZnSOD activity was higher in c ontrols (290 +/- 91 U mg(-1) tissue) than in MND patients (197 +/- 81 U mg(-1) tissue). The reduction in CuZnSOD was compensated for by a co ncomitant elevation of MnSOD activity (control = 123 +/- 40.5 U mg(-1) tissue, MND patients = 175 +/- 47 U mg(-1) tissue). These data not on ly show an important deficit in anterior horn cell body protection aga inst free radical-mediated cell damage, but are also are the first mea surements of SOD isoenzymes in anterior horn neurones.