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United States Department of Agriculture

Agricultural Research Service

Title: Copper Deficiency in Rats Reduces Iron Absorption and Increases the Rate of Iron Loss from the Body

Authors
item Reeves, Phillip
item Demars, Lana

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: February 23, 2004
Publication Date: April 17, 2004
Citation: Reeves, P.G., Demars, L.C. 2004. Copper deficiency in rats reduces iron absorption and increases the rate of iron loss from the body [abstract]. Federation of American Societies for Experimental Biology Journal. No. LB232.

Interpretive Summary: Dietary copper deficiency (CuD) in rats leads to iron (Fe) deficiency anemia. Is this because CuD reduces Fe absorption? Fe absorption in CuD rats was determined by using 59Fe and whole-body counting (WBC). Two groups, each with 45 male weanling rats, were fed an AIN-93G diet devoid of Cu (<0.3 mg/kg; CuD) or one containing adequate Cu (5.0 mg/kg; CuA). At intervals over the next 42 d, 5 rats per group were killed and blood was drawn for hematocrit, hemoglobin, and other indicators of Fe status. At d-7 and d-25, 5 rats per group were fed 1 g of diet labeled with 59Fe. 59Fe retained was monitored for 10 d by WBC. Rats were killed and 59Fe was measured in various organs. Signs of Fe deficiency, i.e., low hemoglobin, hematocrit, and RBC count, were evident in CuD rats by d-14. At d-7, CuD rats absorbed 95% (p>0.05) as much Fe as CuA rats, but at d-25, CuD rats absorbed only 60% (p<0.001) as much as CuA rats. At d-7, the biological half-life of 59Fe was less (p<0.02) in CuD than CuA rats [geometric mean (+SD, -SD) 63(33, 120) d vs. 225(126, 400) d]. At d-25 the values for CuD and CuA were 24(10, 62) d and 128(111, 147) d (p>0.01), respectively. Apparently, the site of this rapid loss of Fe was through the gut. At d-16 and d-34, CuD rats lost 2 to 3 times more (p<0.01) 59Fe in the feces in a 24-hr period than the CuA rats. Also, 59Fe in the duodenal mucosa of CuD rats was about 2 times higher (p<0.01) than in CuA rats. In a separate 5 wk study, in which CuD rats were replenished with a small amount of Cu (1 mg/kg diet) for 7 d, Fe absorption was 30% higher (p<0.01) in CuD rats than in CuA rats. These findings suggest that Fe deficiency anemia in the CuD rat model is at least partially caused by reductions in Fe absorption and retention.

Technical Abstract: Dietary copper deficiency (CuD) in rats leads to iron (Fe) deficiency anemia. Is this because CuD reduces Fe absorption? Fe absorption in CuD rats was determined by using 59Fe and whole-body counting (WBC). Two groups, each with 45 male weanling rats, were fed an AIN-93G diet devoid of Cu (<0.3 mg/kg; CuD) or one containing adequate Cu (5.0 mg/kg; CuA). At intervals over the next 42 d, 5 rats per group were killed and blood was drawn for hematocrit, hemoglobin, and other indicators of Fe status. At d-7 and d-25, 5 rats per group were fed 1 g of diet labeled with 59Fe. 59Fe retained was monitored for 10 d by WBC. Rats were killed and 59Fe was measured in various organs. Signs of Fe deficiency, i.e., low hemoglobin, hematocrit, and RBC count, were evident in CuD rats by d-14. At d-7, CuD rats absorbed 95% (p>0.05) as much Fe as CuA rats, but at d-25, CuD rats absorbed only 60% (p<0.001) as much as CuA rats. At d-7, the biological half-life of 59Fe was less (p<0.02) in CuD than CuA rats [geometric mean (+SD, -SD) 63(33, 120) d vs. 225(126, 400) d]. At d-25 the values for CuD and CuA were 24(10, 62) d and 128(111, 147) d (p>0.01), respectively. Apparently, the site of this rapid loss of Fe was through the gut. At d-16 and d-34, CuD rats lost 2 to 3 times more (p<0.01) 59Fe in the feces in a 24-hr period than the CuA rats. Also, 59Fe in the duodenal mucosa of CuD rats was about 2 times higher (p<0.01) than in CuA rats. In a separate 5 wk study, in which CuD rats were replenished with a small amount of Cu (1 mg/kg diet) for 7 d, Fe absorption was 30% higher (p<0.01) in CuD rats than in CuA rats. These findings suggest that Fe deficiency anemia in the CuD rat model is at least partially caused by reductions in Fe absorption and retention.

Last Modified: 10/24/2014
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