REDUCED PLATELET CYTOCHROME-C-OXIDASE ACTIVITY IN ALZHEIMERS-DISEASE

We evaluated a simplified method for preparation and analysis of plate let cytochrome c oxidase activity in Alzheimer's disease (AD) and cont rol patients. Mean cytochrome c oxidase activity in controls (n = 17) was 0.233 sec(-1)/mg whereas mean cytochrome c oxidase activity in Alz heimer patients (n = 19) was 0.193 sec(-1)/mg, p = 0.033. Complex III (ubiquinol:cytochrome c oxidoreductase), complex II (succinic dehydrog enase), and citrate synthase were all assayed as internal controls and were not significantly different in controls and Alzheimer patients. There is a relatively specific loss of platelet cytochrome c oxidase a ctivity in Alzheimer disease patients.