FIGURE 1.

Damnacanthal treatment induces specific release of PMN secondary granules. Freshly isolated PMN were treated with damnacanthal (Damn) of varied concentrations and other inhibitors for 15 min at 25 °C. A control treatment was performed using vehicle (DMSO) of the same dilution (0.1%). After centrifugation to pellet cells, PMN degranulation was assessed by assaying different granular markers in the cell-free supernatants. Positive degranulation controls were performed by stimulation of PMN with 1 μm fMLF with and without an addition of 10 μm CB. Concentrations of LY94002, piceatannol, SB203580, genistein, and PD98059 used in the treatment were the same as those in Table 1. A, assaying secondary granule release by measuring lactoferrin in the supernatants. B, assaying primary granule release by measuring MPO activity in the supernatants. C, assaying tertiary granule release by zymogram detecting gelatinase in the supernatants. The arrows indicate the two major forms of gelatinase (92 and 56 kDa, respectively) in PMN. As shown, damnacanthal specifically and dose-dependently induced secondary granule degranulation. Data (mean ± S.D.) represent more than five independent experiments. *, significant degranulation.