Fig. 2

⁵⁵Fe-Tf brain uptake in males and females. Samples are reported as DPM per gram of brain tissue. In males, increasing levels of apo-Tf in the brain significantly increases ⁵⁵Fe-Tf uptake into MVs (A) and release into the brain (B). Additionally, increasing levels of holo-Tf results in significantly reduced ⁵⁵Fe-Tf uptake compared to infusions of apo-Tf. This difference is further demonstrated when MV and parenchyma fractions were pooled for total uptake in the whole brain (C). However, in females, the ratio of apo- to holo-Tf in the brain has little regulatory effect on ⁵⁵Fe-Tf uptake into MVs (D), release into the parenchyma (E), and total uptake in the whole brain (F). n = 5 for all conditions, means of biological replicates ± SD were evaluated for statistical significance using one-way ANOVA with Tukey’s posttest for significance. * p < 0.05, ** p < 0.01, *** p < 0.001