UNALTERED ACONITASE ACTIVITY, BUT DECREASED COMPLEX-I ACTIVITY IN SUBSTANTIA-NIGRA PARS-COMPACTA OF PATIENTS WITH PARKINSONS-DISEASE

Substantia nigra pars compacta of seven patients who had died of Parki nson's disease, has been investigated for the iron-depending aconitase (reactions I and II). In addition we analysed respiratory chain enzym es. While complex I activity of the respiratory chain was significantl y reduced, other enzymes of this pathway were unaltered. The citric ac id cycle enzyme aconitase (reactions I and II) showed no difference be tween patients and controls. Thus this ferrous iron dependent and oxid atively sensitive enzyme is not affected by the unphysiological high a mount of ferric iron and the 'oxidative stress' present in substantia nigra of parkinsonian patients.