Effects of iron overload on duodenal iron metabolism and health in rats

Iron is an essential trace element for various physiological functions, yet excessive iron is highly toxic owing to its redox activity property. Male Sprague-Dawley (SD) rats, aged 6~7 weeks were randomly divided into a control group and an iron overload group. They were administered either saline or 150 mg/kg iron dextran for four consecutive weeks. The results show that iron overload significantly reduced body mass and increased serum iron, transferrin-bound iron, ferritin levels, and transferrin saturation. Elevated iron contents were observed in the duodenum, liver, and spleen of iron overloaded rats, whereas duodenal villus length and the villus-length-to-crypt-depth ratio were significantly decreased. Furthermore, an upregulation of DCYTB, DMT1, FTL, and FTH associated with absorption and storage, was observed in iron-overloaded rats, yet no significant changes were found in ferroportin (FPN) or serum ferritin levels. These findings indicate that iron overload induces duodenal iron deposition and intestinal damage by upregulating the expression of duodenal iron-absorption and storage proteins, thereby providing theoretical evidence for duodenal health issues caused by iron overload.