Free radical formation in autopsy samples of Alzheimer and control cortex

The formation of free radicals in homogenates of frontal cortex from brains taken at autopsy and verified histologically to be from five patients with Alzheimer's disease or from six age matched normal controls, was measured by electron paramagnetic resonance spectroscopy. During incubation at 37 degrees C, the formation of free radicals by Alzheimer's samples was 22% higher (P < 0.05) than controls. Following incubation in the presence of ferrous sulfate (200 microM), samples of Alzheimer's frontal cortex produced nearly 50% more free radicals than did controls (P < 0.01). Although these post mortem in vitro observations are consistent with an increased free radical burden in tissue from patients with Alzheimer's disease, that comparable differences exist in vivo between Alzheimer's patients and non-demented people remains to be demonstrated.