Increased intestinal iron absorption in rats with normal hepatic iron stores. Kinetic aspects of the adaptative response to parenteral iron repletion in dietary iron deficiency.
Male Sprague-Dawley rats were fed an iron-deficient diet for 8 days. After this period, iron stores were repleted in three groups of animals by intravenous administration of iron dextran. In a second set of experiments, iron was administered in the same dose as Fe nitrilotriacetic acid complex. 12 h, 24 h and 48 h thereafter, the intestinal iron transfer in vitro and in vivo as well as the non-heme iron and ferritin content were determined in both the liver and the jejunal mucosa. In iron deficiency, intestinal iron transfer is increased to 230% of untreated controls, while non-heme iron and ferritin decreased to 20% and 10% in the liver and to 55% and 25% in the mucosa, respectively. 12 h and 24 h after parenteral administration of 0.1 mmol Fe/kg body weight iron transfer was as high as in iron deficiency, while liver iron stores were not significantly different from the untreated controls. In this situation, the close link between decreases in body iron stores and increases in iron transfer was temporarily dissociated. This can be related to the time lag between the incorporation of parenterally applied iron in the liver and in the jejunal mucosa. The data provide evidence for the hypothesis that the hepatic iron stores have no means of neural or hormonal communication with the small intestine in order to adapt iron transfer to their state of repletion on short notice. Intestinal iron transfer returned to control levels after 48 h.
Schümann
K
K
Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität, München, F.R.G.
Elsenhans
B
B
Ehtechami
C
C
Forth
W
W
D000222:Adaptation, Physiological; D000818:Animals; D005290:Ferric Compounds / Q000008:administration & dosage / Q000627:therapeutic use; D005293:Ferritins / Q000378:metabolism; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007501:Iron / Q000378:metabolism / Q000493:pharmacokinetics*; D000090463:Iron Deficiencies; D007505:Iron-Dextran Complex / Q000008:administration & dosage / Q000627:therapeutic use; D007583:Jejunum / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D009571:Nitrilotriacetic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use; D051381:Rats; D011919:Rats, Inbred Strains
D005290:Ferric Compounds; D007505:Iron-Dextran Complex; D005293:Ferritins; D007501:Iron; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate