Mechanisms of heme iron absorption： Current questions and controversies

• Published in: World journal of gastroenterology : WJG Vol. 14; no. 26; pp. 4101 - 4110
• Main Authors: West, Adrian-R, Oates, Phillip-S
• Format: Journal Article
• Language: English
• Published: United States M311 Physiology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia 14.07.2008; The WJG Press and Baishideng
• Subjects: Absorption; Animals; Biological Transport; Cation Transport Proteins - physiology; Endocytosis; Enterocytes - metabolism; Heme - metabolism; Heme Oxygenase (Decyclizing) - physiology; Heme Oxygenase-1 - physiology; Humans; Iron - metabolism; Iron, Dietary - administration & dosage; Iron, Dietary - metabolism; 亚铁血红素吸收; 人体生理学; 吸收机制; 微量营养素; Receptor mediated endocytosis; Iron; Heme transporter; Heme absorption; Heme oxygenase
• ISSN: 1007-9327; 2219-2840
• DOI: 10.3748/wjg.14.4101

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.