Abstract
Heme iron (HI), derived principally from hemoglobin (Hb) in animal foods, is a highly bioavailable source of dietary iron for humans. Despite several decades of focused research, however, molecular mechanisms governing HI absorption remain undefined. Previous studies in mice and rats have not produced a consensus, definitive model of efficient HI absorption/utilization. We hypothesized that a nutritional approach, using semipurified, HI-containing diets, could be utilized to establish a tractable rodent model of HI absorption that could ultimately be employed to test the roles of receptors, transporters, and enzymes using genetic engineering technology. Experiments were designed to assess HI utilization by feeding animals AIN-93G–based, HI-enriched experimental diets formulated with lyophilized porcine RBCs, containing approximately 85% HI and 15% nonheme iron (NHI). Total iron was within the physiological range (50–75 ppm) and precisely matched NHI control diets containing ferrous sulfate were utilized as comparators. Notably, in Sprague-Dawley (S-D) rats and C57BL/6 (B6) mice, dietary HI effectively (a) resolved iron-deficiency anemia; (b) supported normal pregnancy, lactation, and neonatal development; and (c) contributed to iron loading in Hamp-KO mice and rats (modeling hereditary hemochromatosis). A nutritional paradigm has thus been established that facilitates investigation into mechanisms of HI absorption by S-D rats and B6 mice.
Authors
Jennifer K. Lee, Yue He, Shireen R.L. Flores, Regina R. Woloshun, Xiaoyu Wang, Jacob S. Shine, Pearl O. Ebea-Ugwuanyi, Sitara Sriram, Melissa Fraga, Sean Zhu, Yang Yu, Iqbal Hamza, James F. Collins
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
Having trouble reading a PDF?
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Having trouble saving a PDF?
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.
Having trouble printing a PDF?
- Try printing one page at a time or to a newer printer.
- Try saving the file to disk before printing rather than opening it "on the fly." This requires that you configure your browser to "Save" rather than "Launch Application" for the file type "application/pdf", and can usually be done in the "Helper Applications" options.
- Make sure you are using the latest version of Adobe's Acrobat Reader.
