Mechanism of Excretion of Iron by the Small Intestine: an Experimental Study in Rats with Normal and Abnormal Mucosae

The findings in the present study have demonstrated the presence of two distinct mechanisms of iron excretion by the small intestine in rats. Loss of cell bound iron is the principal pathway of excretion and takes place as epithelial cells are shed off from the tips of villi. The available evidence suggests that the epithelial cells of the mucosa sequestrate iron from a storage pool which might be identical to the labile iron store in man. Transferrin bound iron makes a small contribution to the total loss. An abnormally large amount of iron was excreted in the small intestine of rats infested with Nippostrongylus brasiliensis. At the same time an unduly large amount was also sequestrated by the intestines of these rats. These facts were attributed to increased population of maturing cells in the crypts and the rapid rate of renewal of the villous epithelium.
The morphological appearances of the intestinal villi of the infested rats have a resemblance to those in human subjects with coeliac disease. It is, therefore, suggested that these observations may have some bearing on the status of iron balance in patients suffering from coeliac disease.