Semisoluble aminated glucan: Long-term efficacy against an intraperitonealE. coli challenge and its effect on formation of abdominal adhesions

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Abstract
The first part of this study in the rat was designed to assess the immediate and, in particular, the long-term effects of semisoluble aminated glucan (SAG) with regard to an intraperitoneal (i.p.)E. coli challenge and side-effects. The severity of theE. coli peritonitis was evaluated by quantification of the concomitant bacteremia. The animals randomly received either 10 ml normal saline i.p. (controls) or 10 ml (50 mg) SAG i.p. (experimental groups). It was found that SAG had no immediate protective effect against the infectious challenge as no difference was detected in the bacterial clearance between saline- and SAG-treated rats at day 0. However, 2 days after injection of saline/SAG a substantial protection of SAG was noted as no blood-borne bacteria could be detected at 1, 2, 3, 4 and 5 h after theE. coli challenge in SAG-treated animals, whereas by contrast matching blood cultures were positive in all controls. A likewise protective effect againstE. coli bacteremia of a single i.p. injection of SAG was demonstrated at 7, 21, and 49 days after the administration of the compound. During the 7-week experimental period no clinical side-effects of SAG were observed. At autopsy (days 0, 2, 7, 21, and 49, respectively) no gross pathologic conditions were found. Lung, spleen, and kidney sections from SAG-treated rats were normal, whereas tiny granulomas were exhibited in liver sections, possibly related to the hyperfunctional macrophage state which SAG induced. The second main object of the study was to evaluate SAG's effect on adhesion formation. Intraperitoneal adhesions were induced by excision 1 × 3 cm of the peritoneum and underlying muscle, subsequently closing the defect with interrupted sutures. After closure of the abdominal wall the rats received at random either 10 ml saline or 10 ml SAG i.p. Quantitative assessment of adhesions 1 week later demonstrated a significant (P = 0.05) reduction in SAG-treated rats as compared to controls. Both SAG and dextran 70 are high-molecular weight carbohydrates and the latter is in wide clinical use. The third aim of the study therefore was to elucidate whether dextran 70 also might confer protection against an i.p.E. coli challenge. The data did not support this idea. There was no difference in the number of blood-borne bacteria between dextran- and saline-treated animals.