Figure 4. Rats were injured by instillation of the indicated injury vehicle through an intratracheal catheter. Animals were treated via the same catheter as the injury vehicle with nonspecific goat immunoglobulin G (IgG) or goat anti-rat TNF-[Greek small letter alpha](purified IgG fraction) at the indicated dose. At the time of injury, 1 ml of125I-BSA in 2% BSA (100,000 cpm) was injected into the penile vein. At 5 h postinjury, the albumin permeability index was determined. Horizontal bar indicates mean +/- SD of an uninjured rat group. Parenthetical numbers denote n for the groups above the numbers. *P < 0.05 between the different treatment groups. Permeability index increased for all experimental groups compared with uninjured animals, P < 0.05. [dagger] P < 0.0001 for a synergistic interaction between acid and particulate injury within similar treatment groups.