Fig. 2. Time course of static respiratory system compliance normalized by mouse body weight (C^stat). Pressure–volume curves were obtained by insufflating the lungs with 300 μl air three times to a total volume of 900 μl. For each step, compliance was calculated as the ratio between the insufflated volume and the plateau pressure. The three values were averaged to obtain C^stat. While at 6 h C^statdecreases similarly in the two groups, only in the saline (NaCl) group do the values improve over time. *  P < 0.05  versus NaCl group at the same time point. §  P < 0.05  versus baseline, in hydrochloric acid (HCl) group.