Iron absorption by Belgrade rat pups during lactation.
Thompson K, Molina RM, Donaghey T, Brain JD, Wessling-Resnick M. Iron absorption by Belgrade rat pups during lactation. American Journal of Physiology-Gastrointestinal and Liver Physiology 2007;293(3):G640-G644.
Divalent metal transporter-1 (DMT1) mediates dietary nonheme 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 nonheme iron absorption at the time of weaning, 59FeCl3 was administered to 21-day-old b/b and b/+ rats by intragastric gavage. Blood 59Fe levels measured 5 min to 4 h postgavage 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 postgavage. Combined, these data suggest that DMT1 function is not essential for iron assimilation from milk during early development in the rat.