Iron in Alzheimers and Control Hippocampi - Mössbauer, Atomic Absorption and ELISA Studies

Alzheimer disease is a neurodegenerative process of unknown mechanism taking place in a part of the brain - hippocampus. Oxidative stress and the role of iron in it is one of the suggested mechanisms of cells death. In this study several methods were used to assess iron and iron binding compounds in human hippocampus tissues. Mössbauer spectroscopy was used for identification of the iron binding compound and determination of total iron concentration in 12 control and one Alzheimer disease sample of hippocampus. Mössbauer parameters obtained for all samples suggest that most of the iron is ferritin-like iron. The average concentration of iron determined by Mössbauer spectroscopy in control hippocampus was 45±10 ng/mg wet tissue. The average concentration of iron in 10 Alzheimer disease samples determined by atomic absorption was 66±13 ng/mg wet tissue. The concentration of H and L chains of ferritin in 20 control and 10 AD hippocampi was assessed with enzyme-linked immuno-absorbent assay. The concentration of H and L ferritin was higher in Alzheimer disease compared to control (19.36±1.51 vs. 5.84±0.55 ng/μg protein for H, and 1.39±0.25 vs. 0.55±0.10 for L). This 3-fold increase of the concentration of ferritin is accompanied by a small increase of the total iron concentration.