Figure 2.

Various cAMP elevation agents suppress TNF-α-induced cell death in L929 cells. A, L929 cells were pretreated with or without forskolin (10 μM), PGE₂ (10 μM), epinephrine (Epin, 100 μM), or 6-MB-cAMP (6-MB, 100 μM) for 30 min, followed by stimulation with or without 10 ng/ml TNF-α for 24 h. Cell death was measured by PI staining. The percentages of cell death are shown in the right panel as mean ± SD; n = 3. Left panel is representative of three independent experiments. *p < 0.05. B, L929 cells were treated with forskolin (10 μM), PGE₂ (10 μM), epinephrine (Epin, 100 μM), or 6-MB-cAMP (6-MB, 100 μM) for various times as indicated. Intracellular cAMP was determined using the cAMP enzyme immunoassay kit.