Zymosan-induced neutrophil accumulation dependence on selectin genotype at (A) 4 hours and (B) 8 hours after injection. Tissue MPO content, measured by colorimetric enzymatic reaction and quantitated as units of myeloperoxidase per ear, was determined for each selectin-deficient genotype, and their genetically matched wild-type control (normal expression of both E- and P-selectin) 4 hours and 8 hours after intradermal injection of vehicle (PBS) or 400 μg zymosan. See text for normalized data and statistical comparisons. The bracketed number indicates the number of animals assessed per group. *P ≤ .05 for zymosan-injected E-/P-selectin–deficient mice versus zymosan-injected genetically matched wild-type control and versus zymosan-injected E-selectin–deficient or P-selectin–deficient mice.