Electron paramagnetic resonance analysis of heavy metals in the aging human brain

Electron paramagnetic studies of heavy metals were performed with the use of a Radiopan spectrometer on autopsy material of 5 aged patients (mean age 80.2 years) and 15 control patients (mean age 29 years). The obtained results lead to the following conclusions: 1. The aging brain is characterized by a tendency to decrease in concentration of isolated Cu2+ ions, and a marked decrease in concentration of Fe3+ ions as well as of free radicals, whereas the concentration of Cu2+ clusters is significantly increased. 2. The cases showing both arteriosclerotic and senile degenerative changes are characterized by higher concentrations of Cu2+ clusters than the brains with dominance of the arteriosclerotic process, whereas the concentrations of isolated Cu2+ and Fe3+ ions as well as that of free radicals do not differ between the two subgroups. 3. The diminished concentrations of Cu2+ and Fe3+ ions and free radicals observed in brains of old persons and concomitant with increased concentration of multi-ion aggregates (clusters), more marked in cases of senile atrophy of Alzheimer type, seem to result from some slow-down of metabolic processes in the aging brain.