Organ iron content differs in β-thalassemia intermedia versus major. (A) Iron content (μg/mg dry weight), (B) organ weight (g), and (C) total iron (μg) of liver, spleen, kidney, and heart. The mice have been categorized according to their age as indicated in Figure 2. Mice receiving transplants are ■, +/+; ▩, th3/+; □, th3/th3; gray striped, th3/+ transfusion; white striped, th3/th3 transfusion. Error bars represent SD performed on 3 to 11 independent mice/tissue in duplicate per group for 90 mice sampled. *P < .05, **P < .01, and ***P < .001 relative to control using the Dunnett multiple comparison test. In the heart, the iron content did not increase in mice given a transplant compared to those not so treated (Figure 2A) and comparing (th3/th3)^tp-2M to (th3/+)^tp-2M. This indicates that, at least in mice, increasing the body iron content by augmented intestinal absorption or by indirect administration of iron through blood transfusion does not lead to increased accumulation of iron in this organ over time. This was also confirmed by Prussian blue staining (not shown).