COMPARISON OF FERROUS AND FERRIC IRON BIOAVAILABILITY FOLLOWING RAT CECAL INFUSION

The comparison of ferrous and ferric iron bioavailability following ce cal infusion was studied in ileally fistulated rats. Rats were divided into four groups of 10 rats after recovery from surgery. Group 1 (con trol) was given an iron-adequate diet (45 mg Fe/kg diet) and infused w ith NaCl solution (150 mM). Group 2 was given an iron-deficient diet ( 8 mg Fe/kg diet) and infused with NaCl solution. Group 3 and 4 were gi ven an iron-deficient diet and infused with ferrous sulfate [Fe(II)] s uspension or ferric sulfate [Fe(III)] solution (800 ppm as Fe, pH 6.8) to provide the same amount of iron as that consumed one day before by the control group. NaCl, Fe(II) and Fe(III) were infused through the fistula at two times (1000h and 1800h) for 28 days. The volume of NaCl infused was about equal to the volume of Fe(II) and Fe(III) suspensio n or solution infused. Compared with the control group, body mass gain and food intake for Group 3 and 4 did not decrease. However, the hema tological indices and total iron contents in the liver and spleen for Group 3 and 4 did not decrease. However, the hematological indices and total iron contents in the liver and spleen for Group 3 and 4 showed 20 to 30% and 30 to 40% lower, respectively, compared with those of th e control group. There was no significant difference between Group 3 a nd 4 on iron bioavailability. These results suggest that the lower par t of the digestive tract plays an important role in iron absorption.