RU2634041C1 - Method for simulating general purulent peritonitis in wistar rats - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: to simulate general purulent peritonitis in rats under inhalation halotane anesthesia, a head of blind colon is removed from the abdominal cavity in Wistar rats. Necrosis of the blind gut is carried out by imposing a ligature on the head. At the same time, 2 ml of fresh filtered fecal autosuspension is injected into the lumen of the ligated section of the blind gut.

EFFECT: method is characterized by a one hundred per cent result of the peritonitis development, the simplicity of modeling, the survival of laboratory animals in 60,6 percent of cases for more than 7 days, which is important for developing a new method of treatment and studying the basic pathophysiological mechanisms of the disease.

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Description

The invention relates to medicine, namely to experimental surgery, and can be used to model diffuse purulent peritonitis in rats.

There is a method for modeling peritonitis in Wistar rats, based on the implementation of cecal necrosis [1]. The method is based on performing perforations in the avascular zone of the cecum dome in 6-8 places with an injection needle on different sides of the intestine. With this method, rat survival is less than 7 days, which does not allow us to evaluate the main pathophysiological mechanisms of peritonitis development.

There are various methods for simulating peritonitis in experimental conditions, such as: the introduction of fecal self-suspension by the puncture method; Suspension introduction Aureus strain 209P into the abdominal cavity; longitudinal section of the transverse colon; complete intersection of the small intestine [2, 3, 4, 5]. The negative points are: the life of the laboratory animal is less than 7 days, technical difficulties in reproducing the model of the experiment.

The objective of the proposed method is to create a model of diffuse purulent peritonitis in laboratory rats of the Wistar strain to further study the pathophysiological mechanisms of peritonitis development.

The problem is solved due to the fact that necrosis of the cecum is carried out by applying a ligature in the area of the dome of the cecum and simultaneously introducing fecal autoprecipitation into the lumen of the ligated portion of the intestine.

The method is as follows: under inhalation fluorotan anesthesia, Wistar rats weighing 200-250 g were treated with an operative field, after a dry shave of the anterior abdominal wall was performed. After laparotomy, the dome of the cecum was removed from the abdominal cavity of the animals. Necrosis of the cecum was carried out by applying a ligature to the dome; at the same time, 2 ml of fresh filtered stool was added to the lumen of the ligated portion of the dome of the cecum into the avascular zone. A suspension was obtained by mixing 0.5 ml of sterile isotonic NaCl solution and 0.25 grams of feces from intact animals obtained by filtering it through a double layer of gauze. Auto-suspension was introduced no later than 10 minutes after its preparation. The amount of fecal suspension introduced was sufficient for the development of purulent spilled peritonitis. The surgical wound was sutured in layers. The animal was withdrawn from anesthesia sleep. During the experiment, the clinical picture of the pathological process was observed. The experiment was carried out in compliance with the principles of humane treatment of animals, as well as the requirements of the international community “European Convention for the Protection of Vertebrates Used for Experimental and Other Scientific Purposes” (Strasbourg, 1986). A total of 33 rats were used in the experiment.

All animals removed from the experiment and dead were subjected to pathological examination. Among experimental animals, mortality in the first three days was 39.4% (13 laboratory rats), which indicates both the severity of the developing pathological process and the characteristics of individual reactivity. In the period of 7 days, 20 rats survived, which amounted to 60.6%. The clinical picture of acute peritonitis was more pronounced 6 hours after the start of the experiment; general condition, adynamia, lack of appetite, a decrease in the severity of unconditioned reflexes, a decrease in motor excitement in response to palpation of a swollen abdomen were noted. Progressive inspiratory dyspnea and severe tachypnea developed.

A pathological study in laboratory animals revealed hyperemia of the parietal and visceral peritoneum, bloating of the intestines, the presence of a turbid effusion with a smell (table No. 1).

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The proposed method is characterized by a 100% result of the development of peritonitis, simplicity of modeling, survival of laboratory animals in 60.6% of cases for more than 7 days, an increase in the lifespan of laboratory animals is important for developing new methods of treatment and studying the main pathophysiological mechanisms of the disease.

Literature

1. RF patent No. 2376648, G09B 23/28, Bull. No35, December 20, 2009

2. Fastova I.A., Gubanova E.I. Acute lung damage syndrome in experimental peritonitis // Bulletin of new medical technologies. - 2012. - No. 2 (T. 19). - S. 114-117.

3. Koval EV, Lepekhova SA, Kolmakova S.A. et al. Microbiological control of the course of experimental peritonitis // Siberian Medical Journal (Irkutsk). - 2012. - No. 8 (T. 115). - S. 074-076.

4. Rusin V.I., Zimatkin S.M., Smotrin S.M. Histological assessment of the status of rat peritoneum in experimental peritonitis and its treatment using photodynamic therapy // Journal of Grodno State Medical University. - 2011. - No. 3 (35). - From 21-24.

5. Gozhenko A.I., Vasiliev A.A., Nasibullin B.A. Features of the course of experimental peritonitis in rats when washing the abdominal cavity. // Suite of medicine and biology. - 2014. - No. 2 (44). - S. 111-114.

Claims (1)

A method for modeling diffuse purulent peritonitis in Wistar rats, comprising administering a freshly filtered fecal autosuspension during surgery under fluorotan anesthesia, characterized in that necrosis of the cecum dome is performed by applying a ligature to it and simultaneously introducing fresh filtered fecal autosuspension into the ligation gut lumen This modeling of purulent peritonitis occurs in 100% of cases, and animal survival for more than 7 days is 60.6%.