Fig. 3— Bronchoconstriction in guinea pig (•) and human (▪) precision-cut lung slices induced by different mediators. Concentration–response curves for a) serotonin (•: n = 13, median effective concentration (EC50) = 69 nM; ▪: n = 4, not responsive), b) histamine (•: n = 4, EC50 = 217 nM; ▪: n = 5, EC50 = 2.7 µM), c) leukotriene D4 (•: n = 9, EC50 = 1.8 nM; ▪: n = 5, EC50 = 5.0 nM), d) U46619. (•: n = 4, EC50 = 16 nM; ▪: n = 5, EC50 = 1.3 nM), and e) methacholine (•: n = 6, EC50 = 231 nM; ▪: n = 5, EC50 = 234 nM,). The airway generation used for the measurement was 5 to 8 for the guinea pig and 12 to 16 for human lungs. Data are presented as mean±se as percentage of initial area.