Submitted on April 10, 2007
Accepted on July 18, 2007
Iron Absorption by Belgrade Rat Pups During Lactation
Khristy Thompson1, Ramon M. Molina2, Thomas Donaghey2, Joseph D. Brain3, and Marianne Wessling-Resnick1*
1 Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, United States
2 Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States
3 Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, United States
* To whom correspondence should be addressed. E-mail: wessling{at}hsph.harvard.edu.
Divalent Metal Transporter-1 (DMT1) mediates dietary non-heme iron absorption. Belgrade (b) rats have defective iron metabolism due to a mutation in the DMT1 gene. To examine the role of DMT1 in neonatal iron assimilation, b/b and b/+ pups were cross-fostered to F344 Fischer dams injected with 59FeCl3 twice weekly during lactation. Tissue distribution of the radioisotope in the pups was determined at weaning (day 21). The b/b pups had blood 59Fe levels significantly lower than b/+ controls, but significantly higher 59Fe tissue levels in heart, bone marrow, skeletal muscle, kidney, liver, spleen, stomach, and intestines. To study the pharmacokinetics of non-heme iron absorption at the time of weaning, 59FeCl3 was administered to 21-d-old b/b and b/+ rats by intragastric gavage. Blood 59Fe levels measured 5 min to 4 h post-gavage were significantly lower in b/b rats, consistent with impaired DMT1 function in intestinal iron absorption. Tissue 59Fe levels were also lower in b/b rats post-gavage. Combined, these data suggest that DMT1 function is not essential for iron assimilation from milk during early development in the rat.
