FIGURE 3.

High iron promotes cardiac DOX retention. (A,B) H9C2 cells were treated with ferric ammonium citrate (FAC) or deferoxamine (DFO) and DOX (10 µM) as indicated in the Methods section. ABCB8 protein expression was determined by western blot analysis and normalized to α-tubulin levels. Discontinuities between non-adjacent lanes of the same membrane were indicated by a solid line. (C–E) After 48 h of FAC or DFO treatment, cells were incubated with DOX (30 µM) for 3 h DOX fluorescence was measured at the indicated times. Results are representative of four independent experiments (C). DOX fluorescence was quantified over time (D). AUC was determined from the DOX retention plot (E). Data were expressed as mean ± SEM. Statistical significance was assessed using the Student’s t-test or ANOVA with Tukey’s post-hoc comparisons. *p < .05 vs. control. Scale bar = 10 µm.