Editorial
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Jul 14, 2008; 14(26): 4101-4110
Published online Jul 14, 2008. doi: 10.3748/wjg.14.4101
Mechanisms of heme iron absorption: Current questions and controversies
Adrian R West, Phillip S Oates
Adrian R West, Phillip S Oates, M311 Physiology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia
Author contributions: West AR wrote the review and performed all experiments, Oates PS supervised the writing and experimental process.
Correspondence to: Phillip S Oates, M311 Physiology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia. poates@cyllene.uwa.edu.au
Telephone: +61-8-64881391
Fax: +61-8-64881025
Received: March 26, 2008
Revised: June 2, 2008
Accepted: June 9, 2008
Published online: July 14, 2008
Abstract

Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heme iron is absorbed by different mechanisms than non-heme iron, but despite considerable study over many years these mechanisms remain poorly understood. This review provides an overview of the importance of heme iron in the diet and discusses the two prevailing hypotheses of heme absorption; namely receptor mediated endocytosis of heme, and direct transport into the intestinal enterocyte by recently discovered heme transporters. A specific emphasis is placed on the questions surrounding the site of heme catabolism and the identity of the enzyme that performs this task. Additionally, we present the hypothesis that a non-heme iron transport protein may be required for heme iron absorption and discuss the experiences of our laboratory in examining this hypothesis.

Keywords: Iron; Heme absorption; Receptor mediated endocytosis; Heme transporter; Heme oxygenase