FIG. 2.

The inhibitory action of Z-VAD-FMK on NO production in LPS-stimulated RAW cells. (A) The effect of Z-VAD-FMK pretreatment on LPS-induced NO production in RAW cells. RAW cells were pretreated with various concentrations of Z-VAD-FMK for 30 min. Z-VAD-FMK-pretreated RAW cells were incubated with LPS (1 μg/ml) for 24 h. (B) The effect of exposure time of RAW cells to Z-VAD-FMK on LPS-induced NO production. RAW cells were exposed to Z-VAD-FMK (100 μM) for the indicated periods. Z-VAD-FMK-pretreated RAW cells were incubated with LPS (1 μg/ml) for 24 h. (C) The effect of Z-VAD-FMK posttreatment on NO production in LPS-pretreated RAW cells. RAW cells were pretreated with LPS (1 μg/ml) for the indicated periods. After LPS pretreatment, the cells were washed and cultured with Z-VAD-FMK (100 μM) for 30 min, and subsequently incubated with, LPS (1 μg/ml) for 24 h.