Authors: A H Laftah K B Raja G O LatundeDada T Vergi A T Mckie R J Simpson T J Peters
Publish Date: 2004/09/15
Volume: 84, Issue: 3, Pages: 177-182
Abstract
In this study wellcharacterised animal models of altered iron metabolism were used to investigate links between haem biosynthesis and intestinal iron absorption Mice rendered iron deficient by feeding a lowiron diet for 3–4 weeks showed low levels of hepatic nonhaem iron and hepcidin mRNA with reduced urinary 5aminolaevulinic acid ALA excretion and enhanced intestinal iron absorption Hepatic ALA synthase activity was reduced while ALA dehydratase activity was increased Ironloaded mice had markedly increased liver nonhaem iron and hepcidin mRNA with increased urinary ALA excretion Intestinal iron absorption was decreased mainly due to a reduction in transfer of absorbed iron from mucosa to the carcass Hepatic ALA synthase activity was increased and ALA dehydratase activity moderately reduced Mice exposed to hypoxia 05 atm for 1–3 days had reduced hepatic hepcidin mRNA and urinary ALA excretion while intestinal iron absorption was increased Hepatic ALA synthase activity was reduced The ALA dehydratase activity in liver and spleen was markedly enhanced Injection of ALA to irondeficient mice or hypoxic mice reduced their intestinal iron absorption to normal levels This study further supports the hypothesis that alterations in haem biosynthesis influence duodenal iron absorption ALA in particular appears to function as a modulator in controlling intestinal iron absorptionThis work was supported by the UK Medical Research Council We are grateful to Dr A Deacon for advice and assistance We are also grateful to Mr Jim Keating and other staff members in King’s College Hospital Department of Clinical Biochemistry and Biological Services Unit for their assistance
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