Objective. To study the effect of aminoguanidine at the course of acute experimental peritonitis.

Materials and methods. The experiments were carried out on male rats (n=111), divided into 3 groups and intraperitoneally injected with: group 1 (control) — 0.9 % sodium chloride, group 2 (experimental peritonitis, EP) — 15 % fecal suspension, 0.6 ml/100 g, group 3 (EP+L-AG) — 15 % fecal suspension, 0.6 ml/100 g, followed by intramuscular administration of aminoguanidine, 15 mg/kg (Sigma, USA). In each group researches for the severity of intoxication syndrome, changes in the quantitative composition of leukocytes in blood and peritoneal fluid and its functional activity, the level of nitrites/nitrates, parameters of the prooxidant-antioxidant state and desquamation of the endothelium of blood vessels were carried out in half a day (n=6), 1 day (n=6) and 3 days (n=6), the lethality of the animals was assessed (n=19). Changes in the structure of the peritoneum were studied in microslides of the abdominal wall and ileum, taken from rats in half a day and 3 days of peritonitis.

Results. An increase in motion activity and muscle strength, decrease in rectal temperature and respiratory rate, decline in lethality, a less level of leukocytosis and dislocation of differential leukocyte count to the left in the blood and peritoneal fluid, increase in the quantity of formazan-positive neutrophils, decrease in the level of nitrite/nitrates and malondialdehyde, increase in the concentration of reduced glutathione, decrease in the quantity of circulating endotheliocytes in blood and structural changes in the peritoneum of rats with experimental peritonitis and administration of aminoguanidine were detected, in comparison with the results in peritonitis without its use.

Conclusion. Administration of an inducible NO-synthase inhibitor, aminoguanidine, to rats with experimental peritonitis made corrective effect in relation to removal of negative effects of excessive concentrations of nitrogen monoxide.