Regional brain iron, transferrin receptor and transferrin levels in iron deficient anemic rats

This study sought to gain understanding of the effect of iron deficiency anemia (IDA) on regional brain iron, transferrin receptor (TfR), and transferrin (Tf) in the developing rodent brain. Male weanling Sprague-Dawley rats were used for this study. One group (n=10) received AIN-76A control diet with 35 ppm Fe (CN) and the second group the same diet without iron (<5 ppm Fe) for 28 days. Anemia was verified in the IDA group via hemoglobin (Hb)=5.3 g/dL. After sacrifice, brains and livers were rapidly removed and the brains dissected into eight regions. Each region was pooled and analyzed by tissue ELISA or immunoblot for TfR and Tf. Iron analysis was performed by atomic absorption spectrophotometry. As noted previous studies, regional iron levels were significantly lower (p<0.05) in IDA compared to CN with significant variation by brain region. TfR and Tf responses to IDA were most pronounced in cortex, a region that did not have a large drop in iron content. Other regions like cerebellum, striatum, and thalamus had no response to IDA. None of the responses were as pronounced as in liver. These data indicate a heterogeneous response to IDA by the brain with respect to brain iron, TfR, and Tf levels and suggest that some regions may use mechanisms other than the Tf-TfR route for regulating iron movement.