CHARACTERISTICS OF CHANGES IN RATS WITH ACUTE EXPERIMENTAL PERITONITIS

Background. The lack of decrease in lethality with diffuse peritonitis may be due to a result of the incomplete understanding of the mechanisms of its development. The aim of the research was to study the changes in rats with acute experimental peritonitis. Material and methods. The experiments were carried out on male rats (n=74) divided into 2 series and intraperitoneally injected with: series 1 (control) – 0.9% sodium chloride, series 2 (experimental peritonitis, EP) – 15% fecal suspension, 0.6 ml/100 g. In each group the research was performed in half a day (n=6), 1 day (n=6) and 3 days (n=6) after peritonitis modeling along with the assessment of rats lethality (n=19). The signs of intoxication, the reaction of blood and peritoneal leukocytes, the nitrite/nitrates level and parameters of prooxidant-antioxidant status, the degree of damage to vascular endothelium and peritoneum in rats with peritonitis were analyzed. Results. The decrease in motor activity and muscular strength, the development of fever and tachypnea, leukocytosis in the blood and peritoneal fluid with the increase in quantity of neutrophils and macrophages, appearance of metamyelocytes and myelocytes with the decrease in the percentage of peritoneal formazan-positive neutrophils, reduction in lymphocytes quantity and the lack of eosinophils, rise in concentrations of nitrites/nitrates and lipid peroxidation product – malondialdehyde along with the decrease in the level of antioxidant – reduced glutathione, increase in the quantity of circulating endothelial cells in blood and significant changes of the peritoneum structure were revealed in rats with peritonitis. Conclusions. The research of changes in rats with acute experimental peritonitis has revealed the signs of marked intoxication, changes in the leukocyte differential count of blood and peritoneal fluid in type of neutrophilicmacrophageal leukocytosis with a hyperregenerative shift of leukocyte differential count to the left and impaired ability of peritoneal neutrophils to phagocytosis along with lymphopenia and aneosinophilia, the increase in the level of nitrites/nitrates, development of oxidative stress, lesion of vascular endothelium and significant changes of peritoneum structure.