FIGURE 11.

Effects of PT and wortmannin on intracellular calcium response and MPO release to histone H4. Intracellular free calcium changes in neutrophils on exposure to 40 μg/mL histone H4 for 20 min were measured by detecting the fluorescence of Fura‐2 AM loaded cells. Before adding H4 to neutrophils, cells were untreated or pretreated with 500 ng/ml pertussis toxin (PT) for 1 h or 1 μM wortmannin for 10 min (A). (B) Fold changes of area under the curve (AUC) from (A). H4 again caused significant elevation of intracellular calcium but the inhibitors did not reduce this rise. In panel (C), neutrophil MPO release was measured in PBS with calcium and magnesium (H4), or in cells treated with PT or wortmannin (H4/PT or H4/wortman). In addition, MPO release to H4 was measured in PBS without added calcium and magnesium (H4/PBSwo). N = 5. Results are presented as mean ± sem (*P ≤ 0.05, **P ≤ 0.01)