RU2338265C1 - Method of acute peritonitis modelling - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method is carried out as follows: filtered 10% suspension of animal cecum contents in isotonic sodium chloride solution at 1 ml per body 100 g is introduce into abdominal cavity of laboratory animal of the same kind. Suspension is introduced not later than in 20 minutes after it is prepared.

EFFECT: method allows for simulation of near-clinic pathological situation in experiment.

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Description

The invention relates to medicine, in particular to experimental surgery.

Closest to the claimed solution is a method for modeling acute peritonitis described by A. A. Glukhov and I. N. Banin (No. 98102558/14, Voronezh State Medical Academy named after N. N. Burdenko, 1998), which consists in the introduction of laboratory animals into the abdominal cavity of autologous blood, and then through catheters - microbial suspension from staphylococcus, E. coli, blue-green pus and peptococcus in equal proportions.

The disadvantage of this method is that the modeling of the inflammatory process in the abdominal cavity is complex and time-consuming, it requires the cultivation of microorganism cultures, their complicated dosage and repeated administration. In addition, the proposed ratio of cultures of microorganisms may not always correspond to the microbiocenosis of intestinal contents. The microbial landscape of peritoneal exudate has sufficient variability, as well as species specificity, which is not provided for by the described model. In addition, it involves the introduction of anaerobic microorganisms prepared under aerobic conditions, which cannot but reduce their pathogenicity and virulence.

The objective of the invention is the creation of an etiopathogenetically substantiated controlled method for modeling acute peritonitis, which is close to that developing in a clinical setting.

The task is achieved in that the development of acute peritonitis occurs as a result of exposure to the peritoneum of microorganisms contained in the intestine by intraperitoneal administration of their suspension in a concentration selected experimentally.

The invention is illustrated by drawings.

Figure 1 shows the accumulation of exudate in the left lateral channel in an animal on the first day after modeling peritonitis.

Figure 2 shows a photograph showing hyperemia of the abdominal organs in animals on the first day after modeling peritonitis.

Figure 3 shows the bloating of intestinal loops in the animal on the first day after modeling peritonitis.

Figure 4 shows a micrograph of the peritoneum of the rat on the first day after modeling peritonitis: polymorphic cell infiltration, edema and stasis in the vessels of the microvasculature, color G + E, uv. 8 × 10.

Figure 5 shows a micrograph of a smear of fluid from the abdominal cavity of the animal on the first day after modeling peritonitis:

segmented neutrophils, lymphocytes, macrophages, Romanovsky-Giemsa staining, uv. 8 × 20.

Figure 6 shows a micrograph of a smear of fluid from the abdominal cavity: segmented neutrophils, lymphocytes, single macrophages, detritus of eukaryotic cells and microbial associations of coccal and rod flora, Romanovsky-Giemsa stain uv. 8 × 90.

The method is as follows.

To simulate peritonitis, sexually mature male Wistar rats without signs of disease are used that have been quarantined and kept on a standard food and drink ration under vivarium conditions. An overdose of anesthesia kills one animal. From the contents of the cecum of this animal, a 10% suspension of feces is prepared in an isotonic (0.9%) aqueous solution of sodium chloride. The resulting mixture is twice filtered through a double layer of gauze and then injected into the intact animal under anesthesia by puncture from one injection (in the center of the white line of the abdomen) into the right and left hypochondria, to the right and left iliac regions at the rate of 1 milliliter per 100 grams of animal weight no later than than 20 minutes after preparation (to minimize the loss of anaerobic microflora). In order to avoid damage to the internal organs when the mixture is introduced into the abdominal cavity, the animals are placed vertically, with the caudal end up.

Concrete example

The studies were carried out in the operating unit of the Department of Surgery and Topographic Anatomy of the Kursk State Medical University. All manipulations were performed in compliance with the requirements for the humane treatment of animals (Strasbourg, France, 1986). Pharmacological immobilization and anesthesia of animals was carried out by intramuscular injection of 2% Rometar solution at a dose of 0.2 ml / kg. An overdose of ether anesthesia was used to kill one rat. The contents of the cecum were removed, weighed, ex tempore prepared 10% mixture with isotonic sodium chloride solution. Then it was twice filtered through a double layer of gauze. After that, the suspension obtained was injected for 20 minutes from one (in the center of the white line of the abdomen) injection into the right and left hypochondria, into the right and left iliac regions at the rate of 1 milliliter per 100 grams of the weight of animal forty mature male Wistar rats.

A day later, mortality was 20%. Surviving animals were removed from the experiment by an overdose of ether anesthesia. During the audit, all individuals in the abdominal cavity revealed a turbid liquid (Fig. 1), intestinal loops were swollen, hyperemic, edematous, the mesenteric vessels were dilated (Figs. 2-3). The anterior abdominal wall, intestinal loops were removed for histological examination, followed by the manufacture of paraffin sections and stained with hematoxylin-eosin and picro-Sirius-red, examined under a light microscope. A smear was prepared from peritoneal fluid and stained according to Romanovsky-Giemsa.

When studying stained sections, there were signs of acute inflammation in the organs and tissues of the abdominal cavity: edema, plethora and stasis in the vessels of the microvasculature, massive cell infiltration of a polymorphic cell nature (Fig. 4).

In the peritoneal fluid, segmented neutrophils, lymphocytes, single macrophages, detritus of eukaryotic cells and microbial associations were found, which were two groups of microorganisms: many cocci, painted in dark blue, located in clusters in all fields of vision, presumably staphylococci, and rod-shaped microorganisms , which according to Romanovsky-Giemsa were colored pink and were presented both in the form of single microorganisms and in pairs (Figs. 5-6).

Thus, the proposed model of acute peritonitis compares favorably with the simplicity of implementation, reproducibility, similarity of clinical, laboratory and pathomorphological changes in all experimental animals, which makes it possible to most adequately reproduce a pathological situation close to the clinic under experimental conditions with the subsequent development and experimental testing of treatment methods for acute common peritonitis .

Claims (1)

A method for modeling acute peritonitis, characterized in that a filtered animal is injected into the abdominal cavity with a filtered 10% suspension of the contents of the caecum of an animal of the same species in an isotonic sodium chloride solution at a rate of 1 ml per 100 g of body weight no later than 20 minutes after preparation suspend.

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