Effect of inhaled APC on airway resistance (R
) and lung elastance (H) in mechanically ventilated mice. Airway resistance and lung tissue elastance were measured hourly in mice subjected to injurious ventilation (high tidal volume (HVt)). Airway resistance (top) in mice of the LVt- 4 hr group was constant throughout the experiment, whereas it trended downwards in mice receiving HVt. From two hours and onward, elastance (bottom) was significantly lower in mice treated with activated protein C (APC) compared with those receiving saline (NS). Mice ventilated with protective (low tidal volume (LVt)) ventilation served as reference (data expressed as mean ± standard deviation; * denotes P < 0.05; one-way analysis of variance for each time-point with post-hoc analysis by Dunnett's test).