Increased glucose uptake in erythroblasts of adult anemic mice is associated with enhanced Glut4 expression. (A) Glucose uptake was assessed in peripheral RBCs isolated from 3 different control adult mice as well as 4 adult mice rendered anemic by PHZ treatment (day 6). Uptake of the nonhydrolyzable glucose analog 2-DG (0.5 μM [2 μCi; 0.074 MBq]) was assayed during a 10-minute uptake at room temperature. All data are presented as mean cpm plus SD of triplicate samples. (B) RBCs from 2 different anemic mice were pretreated in the absence or presence of the Glut inhibitor CytB or the related CytD molecule for 30 minutes. [³H]2-DG uptake was then assayed as in panel A. Relative uptakes are presented, with glucose and DHA uptake in nontreated human erythrocytes defined as 100%. (C) Glut4 protein levels were assessed in RBCs isolated from mice rendered anemic by either PHZ treatment or phlebotomy. Peripheral blood was obtained at day 3 (D3) and day 6 (D6) after the start of treatment; 2 samples are shown for each condition. RBCs from adult mice were used as a control, and protein loading in each sample was monitored by actin staining. The levels of Glut4 relative to actin in each sample were determined by comparison of the respective signals using ImageJ software.