Selective inhibition of COX-2 improves early survival in murine endotoxemia but not in bacterial peritonitis.

Prostaglandins of the E series are believed to act as important mediators of several pathophysiological events that occur in sepsis. Studies were performed to evaluate the effect of cyclooxygenase (COX)-2-specific inhibition on the outcome in murine endotoxemia and cecal ligation and puncture (CLP). We observed a significant time-dependent upregulation of PGE(2) production in both blood and lung homogenates of mice administered lipopolysaccharide intraperitoneally, which was nearly completely suppressed by the administration of the COX-2 inhibitor NS-398. Treatment with NS-398 significantly improved early but not late survival in lipopolysaccharide-challenged mice. On the contrary, elevated PGE(2) levels were found in bronchoalveolar lavage fluid but not in plasma of mice subjected to CLP (21 gauge). Pretreatment with NS-398 failed to significantly improve survival in CLP mice. No significant differences were noted in plasma or lung homogenate proinflammatory cytokine levels or lung neutrophil sequestration between the NS-398-treated and control groups. These results demonstrate that selective COX-2 inhibition confers early but not long-term benefits without affecting the expression of proinflammatory cytokines or the development of lung inflammation.