EFFECTS OF EXPERIMENTAL HEMOSIDEROSIS ON INTESTINAL MORPHOLOGY, PERMEABILITY, AND TISSUE IRON CONTENT

Effects of iron overload on intestinal function and structure are unkn own and were, therefore, investigated. Sprague-Dawley rats were random ized into an iron-overloaded group, which received a single subcutaneo us injection of 1.2 g/kg elemental iron-dextran complex, and placebo-t reated pair-fed controls. Animals were studied after a 10-month observ ation period. Intestinal permeability was assessed by measuring the ur inary excretion of lactulose, rhamnose, and mannitol after oral admini stration, In addition, tissue nonheme iron content was measured, and h istologic examination and morphometric measurements were carried out. The chronic iron-overloaded group showed a significant increase in int estine tissue iron content and stainable iron in the submucosa and mus cularis propria and adipose tissue of the small intestine and lamina p ropria and muscularis mucosa of the large intestine. There was a signi ficant decrease in the crypt depths without discernible change in the intestine permeability to any of the markers used. In addition, the ir on-overloaded animals showed a significant number of iron-laden cells, which primarily consisted of macrophages, fibroblasts, myocytes, and adipocytes. In contrast, no iron-laden cells were present in tissues o btained from the normal control group, Thus, chronic experimental iron overload in rats leads to significant morphologic, but no permeabilit y, alterations of the alimentary tract.