Increased mesenteric, diaphragmatic, and pancreatic interstitial albumin content in rats with acute abdominal sepsis

This study was designed to evaluate the decreased permselectivity of the capillary wall and the resultant higher permeability to macromolecular anionic albumin in septic rats, by quantitative estimation of Evans blue-albumin complexes in interstitial tissue. Septic peritonitis was induced by intraperitoneal injection of Escherichia coli-O6 KS H16. Twenty-four hours after induction of septic peritonitis, intact (healthy, noninoculated animals) and septic rats were perfused with 5 mL/Kg of a solution of Evans blue in normal saline (20 mg/mL in .9% NaCl). In septic rats, the interstitial concentration of Evans blue in mesentery, pancreas, and diaphragmatic muscle was significantly higher than that observed in intact animals. The present observations were made in the same experimental model of abdominal sepsis that showed a substantial reduction in the endothelial negative charge of the mesenteric, pancreatic, and diaphragmatic capillary beds. The evidence obtained from this experiment confirms that the loss of the permselective properties of capillary wall for macromolecular anionic albumin derives from a drastic reduction of its normally present and regularly distributed fixed electronegative charges.