Effects of 1-5(-chloronaphthalene-1-sulfonyl)-1h-hexahydro-1,4-diazepine (ML-9; 100 μM), W-7 (100 μM) and 2,3-butanedione monoxine (BDM) (20 mM), or their combination, on the use of endosomal ⁵⁹Fe for heme synthesis. These reagents were included during the last 30 minutes of period 4 and all of period 5. The results are presented as in Figure 6C (ie, percentage of increase in ⁵⁹Fe-heme from the beginning of period 5).