Figure 5. Fe uptake by T lymphocytes and hepatocytes does not correlate with [FeCit₂].

(A) Speciation plots for Fe-citrate species, calculated for increasing Fe-citrate concentrations maintaining a constant Fe∶citrate ratio of 1∶20 using the Hyperquad simulation and speciation (HySS) program. Predicted relative abundance (%) of the two most common Fe-Cit species at pH 7.4 is marked by a blue vertical line and a red (Fe₃Cit₃) or blue (FeCit₂) dot. (B) Fe uptake by CD3⁺ lymphocytes and HepG2 cells in the presence of increasing Fe-citrate concentrations, maintaining a constant Fe∶citrate ratio of 1∶20 (same conditions as in panel A). Experiments were performed at least three times with three replicates per experiment. Each point represents the mean (n = 3) ±1SD. (C) Regression analysis showing no significant correlation between Fe uptake by CD3⁺ (left) and HepG2 (right) cells with predicted [FeCit₂] concentration at pH 7.4.