Dose-response relation of IL-4–induced eosinophil accumulation in rat pleural cavities.

RPMI (100 μL/cavity; ■) or IL-4 (1250, 2500, or 5000 units/100 μL per cavity; ▪) was injected into rat pleural cavities, and eosinophil migration was quantified 24 hours later. Eosinophil accumulation is expressed as the number of cells × 10⁶ per cavity, and the results are presented as the mean ± SEM value for 4 or 5 animals. A significant difference (P < .001) from levels in RPMI-treated rats is indicated by 2 asterisks.