Figure 7. Induction of apoptosis by iohexol is dependent on activation of the caspase-cascade pathway. Neutrophils were cultured in Rosweli Park Memorial Institute 1640 medium containing 10% platelet poor plasma alone and treated with iohexol 40 mg I ml^-1, with or without zVAD-fmk (100 µM). Apoptosis was assessed at 12 h by flow cytometry. Results expressed as mean percentage of apoptotic cells±standard error of the mean; n=3; *p<0.05 for zVAD-fmk vs control neutrophils; p<0.05 for iohexol treated vs control; p<0.05 for zVAD-fmk+iohexol vs iohexol alone.