Compartmental analysis of intestinal iron absorption and mucosal iron kinetics

Abstract

Body iron balance is normally maintained by regulation of intestinal iron absorption, and it is thought that this control is mediated at the level of the intestinal mucosa. Two examples of altered regulation which serve to illustrate this uncertainty are the compensatory increase in iron absorption that occurs in iron deficiency anemia and the inappropriately increased iron absorption seen in hereditary hemochromatosis, an inherited iron-loading disorder. Although experimental iron overload has been produced in a number of mammalian species, there is no satisfactory animal model of the abnormal control of intestinal iron absorption in hereditary hemochromatosis. To evaluate the regulatory role of each mucosal iron transport step, we examined the relationships between the mucosal rate constants and net iron absorption. The two changes in mucosal iron kinetics observed in iron-deficient beagles were: an increase in mucosal iron uptake and, a decrease in mucosal iron storage.