FIGURE 6.

Carbenoxolone blocks the efflux of ATP and ATP metabolites during chemotherapeutic drug-induced apoptosis. Jurkat T cells were incubated with no stimulus, with 250 ng/ml anti-Fas, 4 h (A and E); 3 μm STS, 4 h (B and F); 20 μm Etop, 8 h (C and G); or 25 μm Dox, 12 h (D and H) in the absence or presence of 100 μm CBX (A–D) or 500 μm CBX (E–H). Samples of the extracellular medium were processed for analysis of summed ATP + ADP + AMP (A–D) or ATP only (E–H). Data indicate mean ± S.E. for n = 2–3 experiments each performed in triplicate. **, p < 0.01; ***, p < 0.001.