Analysis of local and systemic inflammatory responses induced by polymicrobial peritonitis in mice.

BACKGROUND Abdominal sepsis induces a local production of proinflammatory mediators that may trigger both septic shock and organ-system dysfunction. AIMS The present study analyzed exudation, cell migration, and CD11a and CD18 subset cells of both local and systemic responses induced by fecal peritonitis in mice. METHODS Animals were anesthetized and, after performing a midline incision in the abdomen, the cecum was ligated and punctured twice with a needle. Sham-operated animals were included. Some groups were previously treated with Evans blue dye (intravenously) to further evaluate the amount of tissue and abdominal cavity leakages. RESULTS Fecal peritonitis triggered a local inflammatory reaction with an increased number of leukocytes and exudation between 6 and 48 h (p < 0.01). Although CD11a/CD18-positive cells in the abdomen peaked after 24h, a significant decrease of them was detected after 48 h (p < 0.05). At the studied period of time (6-48 h), different degrees of exudation in several organs occurred, whereas a significant late recruitment (24 h) of CD11a/CD18 cells into the lungs was observed. CONCLUSIONS In this model, cell migration and exudation at the site of injury occurred in parallel. However, in the lungs, the recruitment of leukocytes that express CD11a/CD18 adhesion molecules constitutes a non-dependent event in relation to fluid leakage accumulation at this site.