The endothelin B receptor antagonist A-192621 induces cell death. (A) A-192621 induces cell death at 48 and 72 h. LN-229 and SW1088 cells were stained with propidium iodide following treatment with A-192621 and analyzed by FACS. (B) A-192621 induces apoptosis by 72 and 48 h in LN-229 and SW1088 cell lines respectively. Caspase 3/7 activity was adjusted for total cell number. Values are expressed as means of three replicates ± SEM. Symbols for statistical significance as compared with vehicle-treated controls are displayed at the bottom of the figure and are applicable to all panels.