Effect of PACs on PMNs infiltration during carrageenin-induced pleurisy. At 4 h after intrapleural injection of carrageenin, the accumulation of PMNs in the pleural cavity was dramatically inhibited by PACs (10, 30 and 60 mg/kg). Each value is the mean ± s.e. mean of n = 6 experiments. °P < 0.01 versus saline. **P < 0.01 versus carrageenin.