Production of ROS by neutrophils stimulated with recombinant HP-NAP determined by luminol-dependent chemiluminescence assay. A, Human neutrophils (1 x 105 cells) were treated with 0.5 μM HP-NAP and D-PBS, pH 7.2, as a negative control at 37°C. The content of ROS generated from neutrophils was measured continuously by using luminol-dependent chemiluminescence assay as described in Methods. B, The integral chemiluminescence signals calculated from the area under curve and the peak value of chemiluminescence responses of neutrophils stimulated with HP-NAP were used to compare with the control. Data were represented as the mean ± S.D. of one experiment in triplicate (*, p<0.05). Similar results were obtained in two independent experiments.