Fig. 5. Arterial oxygen tension (Paco2; mean ± SEM) in animals undergoing mechanical ventilation with different tidal volumes (VTs) 24 h after intravenous injection of endotoxin (lipopolysaccharide) or phosphate-buffered saline (control). * P < 0.05 versus Paco2at 30 min within group and versus Paco2in the control group at the same time.