Non-Transferrin-Bound Iron (NTBI) Uptake by T Lymphocytes: Evidence for the Selective Acquisition of Oligomeric Ferric Citrate Species
Figure 6
Uptake of citrate reflects the cell membrane binding capacity of each Fe-citrate species.
Cells were incubated for 30∶citrate ratios and then treated with pronase. 14C-citrate radioactivity was measured in the cell lysates (intracellular fraction; A and C) and in the supernatants (membrane fraction; B and D). (A–B) Citrate uptake (A) and cell membrane-binding (B) by HepG2, hepatocytes and CD3+ lymphocytes in conditions of predicted increase of Fe3Cit3. (C–D) Citrate uptake (C) and cell membrane-binding (D) in the presence of increasing Fe-citrate concentrations, maintaining a constant Fe∶citrate ratio of 1∶20. Each point represents the mean (n = 3) ±1SD.