Measurement of loosely-bound iron in brain regions using redox cycling and salicylate.

A sensitive iron assay was developed for measuring non-heme and loosely bound iron in regions of rat brain. The method is based on the salicylate trapping of hydroxyl radicals generated from ascorbate-driven redox cycling of Fe3+-EDTA. This assay has high sensitivity (about 20 nM) because of amplification obtained with redox-cycling and fluorescent detection of the salicylate hydroxylation product, 2,5-dihydroxybenzoate. The assay detects iron as Fe2+ and Fe3+ combined. Values of non-heme and loosely bound iron are given for three areas of cortex, caudate, hippocampus, thalamus and brainstem of the rat brain.