Effects of C1 esterase inhibitor administration on intestinal functional capillary density, leukocyte adherence and mesenteric plasma extravasation during experimental endotoxemia

ObjectiveTo determine the effects of C1 esterase inhibitor (C1-INH) administration on intestinal functional capillary density, leukocyte adherence, and mesenteric plasma extravasation during experimental endotoxemia.Design and settingProspective, randomized, controlled animal study in the experimental laboratory of a university.Subjects42 male Wistar rats.InterventionsThe animals were divided into three groups. One half of the animals of each group underwent studies of intestinal functional capillary density and leukocyte adherence on venular endothelium by intravital fluorescence microscopy. In the other half of the animals mesenteric plasma extravasation (FITC albumin) was determined by intravital fluorescence microscopy. Treatment groups received endotoxin infusion of 2.5 mg/kg per hour (group 2 and 3) and 100 U/kg b.w. C1-INH (group 3) during the 2 h of endotoxemia.Measurements and resultsEndotoxemia resulted in a significant decrease in mucosal functional capillary density (18.5% vs. controls), which was reduced by C1-INH administration (9.5%). Treatment with C1-INH also significantly attenuated intestinal leukocyte adherence in submucosal venules (35% vs. endotoxin group) and mesenteric plasma extravasation (44% vs. endotoxin group).ConclusionsC1-INH administration diminishes endotoxin-induced changes in the intestinal microcirculation during experimental endotoxemia.