Figure 2.

Effects of protein kinase C (PKC) inhibitors on eosinophil degranulation. Purified human eosinophils (5 × 10⁴ cells/well) were stimulated with platelet-activating factor (PAF) (1 µm) or complement 5a (C5a) (100 ng/ml) in the presence or absence of PKC in a human serum albumin-coated plate at 37°. After 4 hr, concentrations of eosinophil protein X (EPX) in the cell-free supernatants were analysed by radioimmunoassay (RIA) as an indicator of eosinophil degranulation. Values are expressed as mean ± standard error of the mean (SEM) for four to seven independent experiments. EPX content in the absence of drug was as follows: medium alone, 92·9 ± 13·9; PAF, 512·9 ± 103·4; and C5a, 417·6 ± 91·9 ng/10⁶ cells (mean ± SEM; n = 8–11). Total cellular EPX content was 2771·7 ± 332·76 ng/10⁶ cells (mean ± SEM; n = 11). *P < 0·05; **P < 0·01; significant differences compared with cells stimulated with PAF or C5a in the absence of inhibitor.