FIG 2.

Platelet activation results in limited neutrophil granule release. Citrated whole blood was stimulated with agonists: buffer, ADP (10 μM), thrombin (0.5 U/ml + GPRP peptide), fMLF (1 μM), fMLF + ADP, or fMLF + cytochalasin B (cytb); then, the supernatants were harvested, and neutrophil granule release products were determined for CD11b (A), MMP-9 (B), N-Gal (C), MPO (D), and HBP (E). Flow cytometry was used to determine CD11b release, and data are expressed as mean fluorescent intensity (A). MMP-9, N-Gal, and MPO levels were determined by ELISA, and data are expressed in nanograms per milliliter. HBP levels were determined by ELISA, and data are expressed as the percentage of the maximum release obtained by cell lysis with Triton X-100. The means ± SEM from at least 4 experiments are shown. A two-tailed paired t test was used to analyze differences between agonist- and buffer-treated samples: **, P ≤ 0.01; *, P ≤ 0.05; ns, nonsignificant.