Signs of iron deficiency in copper‐deficient and control rats fed bovine hemoglobin as the sole source of iron

Abstract

We determined whether hemoglobin (Hgb) as the sole source of dietary Fe could sustain normal Fe status in growing rats. Because adequate Cu status is required for efficient Fe absorption in the rat, we also determined the effects of Cu deficiency on Fe status of rats fed Fe as Hgb. One group of 24 rats was fed a diet containing 5.0 mg Cu/kg (CuA) and another 24 were fed a diet containing <0.5 mg Cu/kg (CuD). Eight rats in each Cu group were fed 35 mg Fe/kg as FeSO4; another group was fed 35 mg Fe/kg as bovine Hgb; and a third group was fed 70 mg Fe/kg as Hgb. After 4 wk, CuD rats were anemic compared with CuA rats. Rats fed Hgb at 35 mg Fe/kg were anemic, but those fed Hgb at 70 mg Fe/kg were not. Regardless of the Fe source, Cu was lower (P<0.001) in the mucosa, serum, liver, spleen, and kidney of CuD rats when compared with that in CuA rats. Mucosal Fe and liver Fe were significantly (P<0.001) elevated, but serum (P<0.001) and kidney (P<0.040) Fe were lower in CuD rats, compared with CuA rats. Cu deficiency had no effect on spleen Fe. Feeding Fe as Hgb at 35 mg/kg lowered (P<0.001) Fe in serum and spleen compared with feeding Fe as FeSO4; however, these parameters were normal in rats fed Hgb at 70 mg Fe/kg. Regardless of the dietary Fe level as Hgb, mucosal and liver Fe were significantly lower than that in rats fed FeSO4. This study showed that adequate Fe status in the growing rat could not be maintained with Hgb as the sole source of Fe.