Mediators of Bz-423–induced apoptosis. (a) Ramos cells were incubated with vehicle or Bz-423 for 1 hour. Fluorescence intensity increased above that of control (shaded histogram) with 5 and 10 μM Bz-423 (green and red histograms, respectively). (b) Time course of changes detected in Ramos cells upon treatment with Bz-423 (10 μM). Data are presented as percent cells with indicated response relative to time-matched vehicle controls. No changes in cells treated with vehicle during this time frame were observed. The error on the DiOC₆[3] curve is sufficiently low that the error bars are not visible. Inset: Cytochrome c release. First lane: purified cytochrome c (20 ng); second lane: cytosolic fraction isolated 5 hours after incubation with vehicle; third and fourth lanes: cytosolic fractions isolated 1 and 5 hours after incubation with Bz-423, respectively. a and b represent data from more than five separate determinations.