THE REMOVAL OF HISTOCHEMICALLY DEMONSTRABLE IRON FROM TISSUE SECTIONS BY BRIEF EXPOSURE TO SODIUM DITHIONITE SOLUTION

Abstract

The iron of phagocyte hemosiderin in human lymph nodes and liver, the iron in phagocytes in the stroma of small intestine villi and colonic mucosa in experimentally induced enterosiderosis of guinea pigs, and the cytosiderin iron of human liver cells and of columnar epithelial cells of duodenal and jejunal villi of the experimentally enterosiderotic guinea pigs is totally removed by a five minute exposure to 1 % sodium dithionite (Na2S2O4) in pH 4.5 0.2 [image] acetate buffer. Removal of the phagocyte iron was much slower with hydrochloric and sulfuric acids, in agreement with previous published reports, and intermediate with 5% oxalic acid. The more finely granular cytosiderins were less resistant to acid extraction of their iron. Iron in all the above locations was unaffected by a 2 day exposure to 1% sodium metabisulfite in 1% acetic acid or by 7 day exposure to 6% ethylenediamine tetraacetic acid at pH 7.5 or pH 4.5. Testing for Fe+++ and Fe++ was done with fresh 1% solutions of potassium ferrocyanide and ferricyanide respectively, both in 0.125 N hydrochloric acid (pH 1.0) with 1 hour reaction times. A 15 minute reaction time was adequate.