Hemorrhagic shock/reperfusion (HS/R) followed by sepsis triggers systemic microcirculatory disturbances that may induce multiple organ failure. The present study evaluated the effects of HS/R and cecal ligation and puncture, followed by necrotic cecal resection/peritoneal lavage (REL) on leukocyte-endothelium interactions at the mesentery. Eighty-one anesthetized Wistar rats (200-250 g) were randomly assigned to a first injury: (1) control-HS-no hemorrhagic shock/no reperfusion group, (2) HS/blood-HS/R with 25% shed blood, and (3) HS/blood + LR-HS/R with 25% of the shed blood + lactated Ringer's solution, 3x shed blood volume. Twenty-four hours post-HS/R, animals were submitted to cecal ligation and puncture and, 24 h thereafter, to REL. Leukocyte-endothelium interactions were assessed by intravital microscopy and intercellular adhesion molecule (ICAM) 1 and P-selectin expression by immunohistochemistry. Lungs were observed for ICAM-1 expression and neutrophil infiltration. Single and double injury induced significant increases in rolling (approximately 2-fold), adherent (approximately 5-fold), and migrated leukocytes (approximately 7-fold); ICAM-1 expression (approximately 1/2-fold), and P-selectin expression (approximately 1/2-fold) at the mesentery compared with control-HS group. REL normalized leukocyte-endothelium interactions at the mesentery in single-injured animals. However, in double-injured rats, adherence and migration of leukocytes decreased but did not normalize. Similar results were observed on ICAM-1 expression and neutrophil infiltration in the lungs from these animals. In conclusion, the current in vivo observation of the mesenteric microcirculation after a double injury followed by REL is a suitable model for the systematic evaluation of the inflammatory reaction at local and distant sites. In addition, data presented herein emphasized the importance of surgical removal of the septic focus in controlling the otherwise lethal sepsis-induced multiple organ dysfunction syndrome.

Nakagawa NK; Jukemura J, Aikawa P, Nogueira RA, Poli-de-Figueiredo LF, and Sannomiya P. In vivo observation of mesenteric leukocyte-endothelial interactions after cecal ligation/puncture and surgical sepsis source control. Clinics. 2007;62(3):321-6. PURPOSE: Cecal ligation and puncture (CLP) has been used as a useful model for the induction of polymicrobial sepsis. Necrotic tissue resection and peritoneal lavage (REL) are the surgical procedures for controlling perforated appendicitis. The aim of this study was to evaluate leukocyte-endothelial interactions in the rat mesentery in vivo after CLP and REL. METHODS: Thirty-seven male Wistar rats (250-300 g) underwent laparotomy and were randomly assigned to the following groups: 1) SHAM; 2) CLP: animals submitted to CLP, 3) CLP+REL: animals submitted to CLP and REL. Mesenteric leukocyteendothelial interactions were studied by intravital microscopy assessed once in each animal (3-5 postcapillary venules, 15-25 µm diameter) 24 hours after intervention. Follow-up was performed in all animals; this included analysis of glycemia, lactate, hematocrit, white blood cell count as well as a functional score that was the sum of scoring on the following parameters: alertness, mobility, piloerection, diarrhea, encrusted eyes, and dirty nose and tail. RESULTS: None of the animals showed significant changes in body weight (265 ± 20 g) or in hematocrit levels (46% ± 2%) during the experimental protocol. Compared to SHAM animals, CLP animals showed an increased number of rolling (2x), adherent, and migrating leukocytes (7x) in the mesenteric microcirculation, an increase in blood glucose (136 ± 8 mg/dL), lactate (3.58 ± 0.94 mmol/L), white cell count (23,570 ± 4,991 cells/mm 3 ) and functional alterations (score 11 ± 1), characterized by impaired alertness and mobility, and presence of piloerection, diarrhea, encrusted eyes, and dirty nose and tail. The REL procedure normalized the number of rolling, adherent, and migrated leukocytes in the mesentery; glycemia; lactate; and white blood cell count. The REL procedure also improved the functional score (7 ± 1). CONCLUSION: Local and systemic inflammation was induced by CLP, while REL completely overcame the inflammatory process.