Administration of rhAPC does not reduce endotoxin-induced cytokine, endotoxin-induced receptor, or receptor-antagonist release in the airways. (A) Cytokines and chemokines present in BALF recovered 16 hours after endobronchial LPS-instillation from volunteers who received rhAPC (•) or placebo (○). Concentrations of IL-8, IL-6, TNF-α, and MCP-1 were quantified by ELISA. (B) Receptor and receptor-antagonist present in BALF recovered 16 hours after endobronchial LPS-instillation from volunteers who received rhAPC (•) or placebo (○). Concentrations of IL-1ra, TNF-RI, and TNF-RII were quantified by ELISA. For panels A and B, solid bars represent the median value for each condition, n = 8 for rhAPC, and n = 7 for placebo. Administration of rhAPC did not significantly modify the release of these proteins, as analyzed by the Wilcoxon unpaired exact test.