Figure 6  .

Effect of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) on apoptosis (Hoechst staining). (A) Data are mean (SEM) for cells which had detached from the plate in three separate experiments with the effect of 1 mM SNAP (shaded bars) determined by paired t test; *p<0.05, **p<0.01. (B) Data are for attached cells in the presence (shaded bars) and absence (clear bars) of 25 µM C₆-ceramide and are mean (SEM) of four separate cell preparations; *p<0.05, **p<0.01 for the difference from the appropriate control by a Newman-Keuls test.