Endotoxin and tumour necrosis factor do not cause mortality from caecal ligation and puncture.

Macrophage tumour necrosis factor-alpha (TNF-alpha) production is thought to represent an important pathogenic mechanism by which Gram-negative sepsis is mediated. We compared the effects of caecal ligation and puncture (CLP) on endotoxin-sensitive (C3H/HeSnJ) and endotoxin-resistant (C3H/HeJ) mice. Mortality after CLP for C3H/HeSnJ mice compared with C3H/HeJ mice was not significantly different (32% and 55%, respectively). When survivors were injected with lipopolysaccharide intraperitoneally on the 7th day after CLP, the mortality rate was 82% for C3H/HeSnJ mice versus 0% for C3H/HeJ mice (P < 0.0001). Serum endotoxin levels at 24 h after CLP were only slightly elevated. Serum TNF levels and peritoneal macrophage TNF production were undetectable in C3H/HeJ mice and were only slightly elevated in C3H/HeSnJ mice by 24 h after CLP. Peritoneal macrophage mRNA levels for TNF-alpha, IL-1 beta, and I-A alpha displayed a similar pattern in the two strains of mice, with a 2- to 3-fold increase in TNF-alpha and IL-1 beta mRNA levels by 24 h and a sharp decrease in I-A alpha mRNA by 24 h. The cause of mortality in mice that undergo CLP cannot be attributed to overwhelming endotoxemia and/or TNF production.