A / Susceptibility of RAW 264.7 undifferentiated cells to various doses of the NO donor compound DETA-NO in culture. RAW 264.7 cells seeded at 5.104 per well in 96 wells plates were cultured in medium alone (●) or medium supplemented with 125 μM (◇), 250 μM (△), 500 μM (□), 1000 μM (O) DETA-NO. The number of live cells recovered at the indicated times was estimated using the MTT reduction test. Similar results were obtained estimating the cell survival either by 3H-thymidine incorporation, or by trypan blue exclusion. B/ Susceptibility of RAW 264.7 either undifferentiated, or differentiated cells, to 1 mM dose of the NO donor compound DETA-NO in culture. RAW 264.7 cells were cultured (10 × 106 cells in 50 ml) in medium alone (○) or medium supplemented with either IFN-γ (50 U/ml – ◆), or LPS (5 μg/ml – ■) or a mixture of IFN-γ (50 U/ml) + LPS (5 μg/ml – ▲). After 24 h, the cells were recovered, washed, seeded at 5.104 cells per well in 96 wells plate, and exposed to 1 mM dose of the NO donor compound DETA-NO for the indicated times. The percentage of living cells was assessed after 48 hours exposure to the NO donor compound using the MTT assay. The experiments were performed in triplicate and the results presented are representative of four separate experiments.