Expression of genes involved in iron metabolism in mouse
intestine.
McKie, Andrew T., Kishor B. Raja, Timothy J. Peters, and Farzin
Farzaneh, Robert J. Simpson.
Department of Molecular Medicine, Kings College School of Medicine
and Dentistry, The Rayne Institute, 123 Coldharbour Lane, London SE5
9NU, Department of Clinical Biochemistry, Kings College School of
Medicine and Dentistry, Bessemer, Road London SE5 9JP
APStracts 3:0106G, 1996.
Intestinal non-haem iron levels and mRNA levels of genes implicated in
iron metabolism were measured in mice with altered iron metabolism
(chronic (4 weeks) and acute (4 days) dietary iron deficiency; iron
overload and hypoxia) in order to investigate their role in the
process and regulation of intestinal iron absorption. Mucosal non
-haem iron levels were decreased by both chronic and acute iron
deficiency, increased by iron overload but not affected by hypoxia.
There was evidence of a gradient of mucosal non-haem iron along the
small intestine (duodenum, jejunum greater than ileum). There were
also regional differences in H-ferritin (duodenum greater than ileum)
and transferrin receptor (ileum greater than duodenum) mRNA levels.
Iron overload produced a decrease in transferrin receptor mRNA in the
duodenum, with ferritin mRNA levels unaffected in both duodenum and
ileum. Chronic iron deficiency induced a 2- fold increase in
transferrin receptor mRNA levels in both duodenum and ileum, whereas
H- and L- ferritin mRNA levels did not change significantly. The
ratio of H/L ferritin decreased significantly during exposure to
hypoxia, however individual ferritin and TfR mRNA levels were not
significantly altered. Calreticulin (mobilferrin), Cysteine Rich
Intestinal Protein (CRIP) and H+-ATPase mRNA levels were virtually
unchanged in all models. Comparison with previously published data on
changes in iron absorption leads us to conclude that: a) iron
absorption can be altered independently of effects on transcripts of
genes for iron-related proteins and b) it is not essential for iron
absorption to be co-ordinated with regulation of mucosal iron
metabolism.
Received 29 November 1995; accepted in final form 19 April 1996.
APS Manuscript Number G507-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96