LACK OF TOPOGRAPHICAL RELATIONSHIP BETWEEN SITES OF ALUMINUM DEPOSITION AND SENILE PLAQUES IN THE ALZHEIMERS-DISEASE BRAIN

Aluminum has been presumed to be involved in the pathogenesis or etiol ogy of Alzheimer's disease. Histochemical demonstration of aluminum in autopsy brains from Alzheimer's disease victims by means of the soloc hrome azurine method in combination with the methenamine silver techni que revealed aluminum-related staining in some neocortical and hippoca mpal senile plaques and tangles, as well as in the cytoplasm and/or th e nuclei of some neurons, and in the cytoplasm of endothelial cells of blood capillaries and pericytes around larger blood vessels, In doubl e-stained samples (first with methenamine silver and then with solochr ome azurine) only some plaques displayed the presence of aluminum, whi le others did not show any sign of the presence of the trace metal. Th e specificity and sensitivity of solochrome azurine staining was check ed in paper spot-test and test-tube experiments combined with flameles s atomic absorption spectrophotometry. The results suggest that alumin um is present in brain samples from Alzheimer's disease victims, but t he structural localization indicates that it is not primarily involved in the etiology of the disease.