Expression of IL-1 family (mRNA levels). Male C57bl/6 mice were exposed to vehicle (aerosolised saline) or LPS (1 mg/ml) for 30 minutes. Lung tissue was collected at different time points after the exposure and mRNA expression of IL-1α (Α), IL-1β (Β), IL-18 (C), IL-1R (D) and IL-18R (E) measured by real time PCR. Data are represented as mean ± S.E.M. for n = 6 animals in each group. Statistical significance was determined using Mann–Whitney U test. # = P < 0.05, denoting a significant difference between the LPS exposed and vehicle exposed wild-type groups.