Mobilisation of iron from peritoneal rat macrophages by desferrioxamine

The amount of radioiron released from rat peritoneal macrophages after phagocytosis of 59Fe labelled erythrocytes can be enhanced by addition of desferrioxamine. The effect is dose dependent and the iron chelated by desferrioxamine appears to be at the expense of ferritin. However, desferrioxamine does not appear to chelate iron already incorporated into ferritin. It seems likely that the iron comes from a labile chelatable pool through which the iron from haemoglobin catabolism passes before being incorporated into ferritin. The desferrioxamine appears to enter the macrophage and chelate iron to form ferrioxamine which subsequently leaves the macrophage. In vivo it was not possible to show substantial iron chelaton by desferrioxamine in rats when 59Fe labelled non-viable red cells were injected intravenously. This suggests that in vivo mobilization of reticuloendothelial iron by desferrioxamine may be of limited significance.