Iron in Parkinson's Disease Revisited

Mössbauer studies of fresh frozen samples taken at autopsy from different parts of the human brain (globus pallidus (GP), substantia nigra (NS), and hippocamp (Hip)) showed a relatively high concentration of iron in these structures. Mössbauer data, biochemical results and transmission electron micrographs lead to the conclusion that in all above-mentioned structures iron is located mainly within ferritin. However, the Mössbauer doublets obtained from most brain samples at 90 K are slightly asymmetric. This asymmetry could be caused by the presence of a small amount of non-ferritin-like iron. Measurements at 4.1 K showed besides the six-line spectra characteristic for ferritin-like iron, an additional doublet with Mössbauer parameters different from ferritin. We found a slightly higher asymmetry and intensity of the 4.1 K doublet in Mössbauer spectra of Parkinsonian SN than in control SN. As Parkinson's disease is a progressive degeneration of nervous cells in SN and iron may be involved in this degeneration process, this may suggest that the factors evoking these phenomena are related to the pathogenesis of Parkinson's disease.