Fig. 2. Bronchoalveolar lavage fluid (BALF) and serum concentrations of tumor necrosis factor-α(TNF-α) in the different experimental groups after 90 (open) and 240 (dashed) min of mechanical ventilation. Data are mean ± SD from groups of 10 animals (except control, n = 16; Salit90/240, LPSit90/240, and LPSip90/240, n = 3; 13/3H, n = 13). BALF: groups LPSit90 and 240 had significantly higher TNF-α levels than all other groups, with levels at 90 min significantly higher than those at 240 min. *Statistically significant (individual comparisons, P < 0.05) vs. all other groups. Serum: statistically significant (individual comparisons, P < 0.05)* vs. all other groups.