Histological study of iron deposits in selenium-deficient rats

Previous studies have shown that selenium (Se) deficiency is associated with hematological abnormalities, which may result in an increased distribution of iron in various tissues. This report describes histological studies of the location of excess iron deposits in tissues. Male Wistar rats were fed a Torula yeast-based Se-deficient [Se(-)] or Se-adequate [Se(+); containing 0.1 mg Se/kg as sodium selenite] diet for 8 or 82 weeks. Excised tissues were embedded in either paraffin or epoxy resin. A dramatic increase was observed in iron deposition in the liver and kidneys of rats on the Se(-) diet. Prussian blue-stained sections under the light microscope showed iron deposits in the parenchymal cells and Kupffer cells of liver and in the proximal tubules of kidneys. The liver and kidneys of Se(-) rats had considerably altered morphology: lysosomes were enlarged and contained electron-dense areas. X-Ray microanalysis showed that the areas that corresponded to the lysosomes contained iron. No iron deposits were observed in sections of kidney and liver from rats fed the Se(+) diet. Thus, these studies identified subcellular sites of iron deposition in the liver and kidneys of Se(-) rats. These iron deposits may be an important factor in the pathogenesis of Se deficiency.