Factors affecting iron balance

Abstract

The availability of radioisotopes of iron led to the performance of physiologic studies of the absorption, excretion, and kinetics of iron. The effects of dietary constituents and intestinal secretions upon iron absorption have been thoroughly explored and have permitted the development of tools for nutritional studies in various geographic areas of the world. The basic mechanisms for regulation of iron absorption are not fully understood. However, the isolation and characterization of newer iron-binding proteins, the existence of mucosal receptors in which there is competition for iron-binding sites with other metals, and the identification of a number of animal models with genetic abnormalities of iron absorption provide promise for development in the foreseeable future. The means by which the body informs the intestine to increase or decrease iron absorption is poorly understood, and the abnormality in hemochromatosis and iron overloading disorders remains unexplained. Much has been learned in recent years regarding the structure of iron-containing proteins and the variations that exist in different species. Similar problems remain to be solved with regard to the intermediary metabolism of iron in red blood cell precursors and other cells in the body. It is postulated that the combined usage of physiologic, biochemical, and immunologic investigations will provide the basic information required.

Iron metabolism in the hemoglobin-deficit mouse: correlation of diferric transferrin with hepcidin expression

“…Transferrin saturation has been a particularly appealing candidate, as diferric transferrin is the major source of iron for most tissues, and particularly for developing erythroid cells. 9,40 Changes in the level of diferric transferrin would thus be expected to reflect the iron requirements of the tissues.…”

A rapid decrease in the expression of DMT1 and Dcytb but not Ireg1 or hephaestin explains the mucosal block phenomenon of iron absorption

“…[1][2][3] As the body cannot actively excrete iron, the body iron content must be regulated at the point of absorption across the mature villus enterocytes of the duodenum. 4 The main stimuli for iron absorption are changes in body iron stores and the demands of the developing erythroid mass.…”

Fetal liver iron overload: the role of MR imaging

“…To the best of our knowledge, the association of liver iron overload and digestive tract anomalies has been reported in only three fetuses, two siblings presenting with a neonatal diagnosis of haemochromatosis who had duodenal atresia [18] and one fetus who had ileal atresia [19]. A possible explanation for this association could be an increase in iron uptake secondary to the altered integrity of the intestinal mucosae [20,21]. We suggest looking for abnormal liver signal in all fetuses referred for MRI for digestive tract anomalies.…”