Both SAHA and 2357 prevent PLA2 activation. Monocytes stimulated for 4 hours with LPS in the absence or presence of 50 nM ITF2357 or 0.5 μM SAHA. The cells were then incubated for 2 minutes with 2 mM ATP and the presence of active PC-PLC or PLA2 in cell lysates was determined. Data are expressed as percent of PL activity of control (LPS-ATP stimulated) cells. PLC activity (mU/μg) and PLA2 activity (nmol/μg per minute) in a representative experiment were, respectively, 1.15 ± 0.002 and 0.44 ± 0.01 after LPS-ATP treatment and 1.21 ± 0.004 and 0.22 ± 0.018 after LPS-ATP treatment in the presence of ITF2357 or SAHA, respectively.