Fig. 1. Study design and measured mean arterial pressure (MAP) in mice during hemorrhagic shock (HS) in the presence or absence of mechanical ventilation (MV). Hemorrhage was induced by blood withdrawal, as described in Materials and Methods. Groups of mice were sacrificed (†) at the start of the experiment (control) or after 90 min of HS. After 90 min of HS, a subgroup of mice was resuscitated and killed 24 h after shock induction. Spontaneously breathing mice (□) were compared with mechanically ventilated mice (▴). Data are expressed as mean ± SD.