Iron and ferritin in hippocampal cortex and substantia nigra in human brain--implications for the possible role of iron in dementia.

The concentrations of iron and of ferritin, the main iron-binding compound in the brain, as well as the sizes of the iron cores of ferritin were assessed in hippocampal cortex (Hip) and substantia nigra (SN) from human control brains, using Mössbauer spectroscopy (MS), ELISA and electron microscopy. 8 Hip and 20 SN samples were measured by MS, 11 Hip and 11 SN were used for ELISA, and the size of the iron cores of ferritin was assessed from measurements of 50 iron cores from Hip-ferritin and 50 iron cores from SN-ferritin. The average concentration of iron in Hip was found to be about one third of that in SN, as was the concentration of H-ferritin, yet L-ferritin was less than one fifth in Hip compared to SN. The size of the average iron core in Hip was assessed to be about 3.1 nm and about 3.7 nm in SN. These results may point to different iron metabolism in these areas, suggesting faster iron turnover in Hip.