Cumulative distribution of airway smooth muscle mass per mm2 of basement membrane (ASM/mm2 of PBM). The values plotted are individual airway measurements. 2–8 airways were quantified per animal. The distribution of the 10 day group was significantly different from both the control and 5 day groups (p < 0.05). n = 38, 40, and 31 for control, 5 days, and 10 days.