Effects of diamide and DEM on depolarization.

Depolarization induced in 10 primary AML cases by 3 μM mClCCP and 100 μM diamide and in 8 cases by 3 μM mClCCP and 100 μM DEM. Cells were preincubated with diamide or DEM for 2 hours before addition of mClCCP. Results are expressed as the mean percentage of control cell depolarization on a scale calibrated by calculating that 100% depolarization is induced by 30 μM mClCCP. Error bars represent SDs. Significance levels refer to Wilcoxon signed-rank analysis of comparisons with the depolarization induced by 3 μM mClCCP alone. Two of 10 samples were not sensitized with diamide, and the range of responses was large: +5% to +43% for mClCCP, −25% to +55% for diamide alone, and −4% to +107% for the combination of the 2. DEM enhanced MTP in 6 of 8 cases (range −176% to +38%) and had no significant effect on mClCCP-induced depolarization.