Effect of inhibition of heme synthesis on intracellular radio-iron distribution during erythroid development. Cells were labeled with 59Fe-human–diferric transferrin during the first 6 days of phase II (EPO-dependent phase, see Materials and Methods), then washed, and reincubated in fresh nonradioactive medium with or without 0.5 mmol/L succinylacetone. (A) Analysis by SDS-PAGE. Equal amounts of cell lysate radioactivity were applied to each lane of a 6% nonreducing SDS-PAGE gel followed by phosphor-imaging. The figure represents a typical result of four independent experiments from four different donors. (B) Analysis by immunoprecipitation and heme extraction. Ferritin was immunoprecipitated from cell lysates with antihuman placental ferritin rabbit serum. Heme was extracted with an ethylacetate-acetic acid (3:1 vol/vol) mixture. The results shown are from cultures of two different normal donors. Both experiments were performed in duplicate.
