The role of iron in neurodegeneration--Mössbauer spectroscopy, electron microscopy, enzyme-linked immunosorbent assay and neuroimaging studies.

The possible role of iron in neurodegeneration was studied by various techniques: electron microscopy, enzyme-linked immunosorbent assay, M?ssbauer spectroscopy, atomic absorption, ultrasonography and magnetic resonance imaging. The measurements were made on human tissues extracted from liver and from brain structures involved in diseases of the human brain: substantia nigra (Parkinson?s, PD), hippocampal cortex (Alzheimer?s, AD) and globus pallidus (progressive supranuclear palsy, PSP). The sizes of the iron cores of ferritin, the main iron storage compound in tissues, were found to be smaller in brain than in liver. Brain ferritin has a higher proportion of H to L chains compared to liver. A significant decrease of the concentration of L chains in PD compared to control was found. No increase in the concentration of iron in PD versus control was detected; however, there was an increase of labile iron, which constitutes only 2? of brain iron. In AD an increase in the concentration of ferritin was noticed, without a significant increase in iron concentration. In PSP an increase of total iron was observed. Our findings suggest that the mechanisms leading to the death of nerve cells in these three diseases may be different, although all may be related to iron mediated oxidative stress.