In vivo leukocyte–endothelium interactions in rat mesenteric microvessels after ischemia/reperfusion and sepsis

Objective

A leukocyte–endothelium interaction is known to be a remarkable event at the beginning of systemic inflammatory response syndrome. The aim of this study was to evaluate leukocyte–endothelium interactions in superfused mesenteric postcapillary venules after hemorrhagic shock/reperfusion and cecal ligation and puncture in rats.

Methods

Thirty-six Wistar rats (200–250 g) were submitted to the following interventions: 0 hours, anesthesia with sodium pentobarbital (50 mg/kg i.p.), hemorrhagic shock (MAP ~40 mmHg lasting 1 hour) and reperfusion with lactated Ringer's solution (3 × shed blood) + 25% of the shed blood; 24 hours, anesthesia and cecal ligation and puncture; 48 hours, anesthesia, cecal resection and peritoneal lavage; and 72 hours, anesthesia and intravital microscopy of the mesentery (venule diameter, 15–25 μm).

Results

Data of leukocyte–endothelium interactions in rat mesenteric microcirculation are presented as the mean ± standard deviation (Table 1).

Table 1 Leukocyte–endothelium interactions in rat mesenteric postcapillary venules

Conclusions

The double-hit model (ischemia/reperfusion and sepsis) induced a severe inflammatory injury similar to sepsis alone. The inflammatory process was overcome by cecal resection and peritoneal lavage. Up to 72 hours of reperfusion with lactated Ringer's solution and 25% of the shed blood volume, inflammation is still evidenced by the increased number of migrated cells in the perivascular tissue.