Figure 3

Survival of U937 cells treated with OUA depends on the activity of NCX. U937 cells were exposed or not to KBR (10 μM) or to Nifedipine (10 μM) or to DMSO for 30 min and then to OUA 100 nM or again to DMSO for 24 h. (a) Cells were fixed and stained with propidium iodide; subG1 events in the cell cycle were evaluated under cytofluorimetry. (b) a portion of unfixed cells cells were counted in a hemocytometer as excluding and not excluding trypan blue. Viability was obtained by calculating live (trypan blue-excluding) cells as a percentage of all counted cells. The reported values represent the means and the error bars the S.D. of the percentage of live cells (trypan blue-excluding) or subG1 events of four independent experiments. Assessment of cell survival was investigated and statistically significant differences (P<0.01) were found between the data obtained in OUA and in (KBR + OUA) treated cells. (c, d) U937 cells were pretreated with KBR (10 μM) for 30 min and then exposed to Monensin (3 μM) or Tunicamycin (1 μM) for 24 h. The reported values represent the means and the error bars the SD of the percentage of live cells (trypan blue-excluding) or of subG1 events of four independent experiments. Assessment of cell survival was investigated and statistically significant differences (P<0.01) were found between the data obtained in MON and in (KBR + MON) treated cells.