FIGURE 2.

Acidosis-mediated protection from glutamine starvation is due to a reduction in apoptosis. A–C, WEHI7.2 cells were incubated in the absence of 2 mm l-glutamine with or without acidification of the medium for the time indicated and then either tested for viability by trypan blue exclusion (A), fixed and stained with PI, then assayed for sub-G₁ DNA content by flow cytometry (B), or analyzed by immunoblotting for appearance of apoptosis markers (C). D, WEHI7.2 cells were incubated in the presence or absence of l-glutamine for 8–10 h and then analyzed by flow cytometry for surface exposure of phosphatidylserine by assessment of Annexin V positivity. E and F, WEHI7.2 cells, either wild type (white bars) or Bcl-2 overexpressing (black bars) were incubated for 12 h in the presence or absence of l-glutamine with or without acidification of the medium, then viability was assessed by trypan blue exclusion assay. Overexpression of Bcl-2 is shown by Western blotting in E. *, p < 0.001.