RU2614885C1 - Models of spinal cord ischemia of laboratory animals - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: for simulation of spinal cord ischemia in laboratory animals, anesthetic preparation "Propofol" is administered. The abdominal aorta and inferior vena cava are selected, ligatures are placed below the point of origin of renal arteries. Collaterals are destroyed by a scalpel, the inferior vena cava is tied up below the renal vessels, and then ligatures are removed from the place of their application.

EFFECT: method provides a persistent ischemia in laboratory animals by intraperitoneal injection of drugs, reduction of animals trauma during operations, a possibility of longer observation of patients without ischemia of the intestine, the lower libs and circulatory disorders of mesenteric veins.

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Description

The invention relates to experimental medicine and can be used when performing scientific work on spinal cord ischemia.

Analogs of the invention

An experimental model of rat spinal cord ischemia with occlusion of the abdominal aorta below the renal arteries. (G.V. Ponomarev, A.A. Shmonin, K.T. Aliyev, T.D. Vlasov E.V. Melnikova, D.G. Smolko, A.A. Skoromets).

Criticism of analogues

However, the known models for creating ischemia of the spinal cord have the disadvantages identified during the experiments: the occurrence of a violation of the blood supply to the intestines, the occurrence of collateral blood supply to the spinal cord, as a result of which repeated surgical interventions are necessary.

Prototype of the invention

An experimental model of rat spinal cord ischemia with occlusion of the abdominal aorta below the renal arteries: G.V. Ponomarev, A.A. Shmonin K.T. Aliev, T.D. Vlasov E.V. Melnikova, D.G. Smolko, A.A. Skoromets (Journal of Translational Medicine, August 2014, pp. 40-45.).

The prototype experiments were carried out in accordance with the Guidelines for the care and use of laboratory animals (publication of the National Institute of Health No. 85-23, USA) and the Guidelines for the experimental (preclinical) study of new pharmacological substances, edited by R.U. Khabrieva (2005). The experiments were performed on 12 Wistar male rats weighing 200-250 g. All surgical interventions were performed in an experimental operating room in compliance with aseptic and antiseptic rules under general anesthesia with chloral hydrate (450 mg / kg), administered intraperitoneally. Experimental animals were divided into two experimental groups. False-operated rats, which were used to isolate the abdominal aorta without occlusion, were assigned to the first (control) one (n = 6); in the second (experimental), the infrarenal section of the abdominal aorta was clamped without reperfusion (n = 6). To model ischemia of the lumbosacral segments of the spinal cord in anesthetized animals, laparotomy was performed, the infrarenal section of the abdominal aorta was isolated, which was ligated with suture silk thread. The surgical wound was sutured. Animals were housed one at a time in a cage. Neurological deficit was assessed after 48 hours on the Tarlov scale. 48 hours after the abdominal aortic ligation, the left ventricle of the heart was punctured with a medical needle and a 4% solution of paraformaldehyde was injected on phosphate buffer to fix the spinal cord. Then, soft tissues of the lumbar region were dissected in layers and the spine was isolated. After laminectomy and intersection of the spinal roots, the spinal cord was removed from the spinal canal. Then it was embedded in paraffin (or celluloidin) and, after solidification, sections of the lumbosacral segments (L2-S4) 5 μm thick were performed on the microtome and stained with thionine according to the Nissl method. Then, under a light microscope with magnification × 100, × 400, the number of neurons of normochromic, hyperchromic shriveled and non-wrinkled and hypochromic shadow cells was counted. Statistical processing of the results was carried out using the program "Statistica 6.0". A nonparametric Mann-Whitney test was used to compare two independent samples. Differences were considered significant at p <0.01.

Prototype criticism

The occurrence of a violation of the blood supply to the intestines, the occurrence of collateral blood supply, resulting in the need for repeated surgical interventions.

The purpose of the invention is to eliminate the occurrence of collateral blood supply without intestinal ischemia.

SUMMARY OF THE INVENTION

The essence of the proposed experimental model is as follows:

the experiment is carried out on laboratory animals (rats).

Training:

1) A sample of animals was made by age and gender.

2) Animals were weighed and the dose of anesthetic drug (propofol) was calculated.

3) The introduction of an anesthetic drug.

4) After 30 minutes, control the depth of anesthesia by pain reflexes.

5) Preparation of the surgical field.

Operation progress:

1) Median laparotomy.

2) Access to the abdominal aorta and inferior vena cava.

3) Isolation of the abdominal aorta and inferior vena cava.

4) Ligature application below the site of renal artery discharge.

5) The destruction of collaterals.

6) Bandaging the inferior vena cava below the renal vessels, removing ligatures and checking hemostasis.

7) Wound closure.

Postoperative period:

1) Check for paresis or paralysis of the lower extremities.

2) Re-opening.

3) The introduction into the left ventricle of 1.0 ml of diamond blue.

4) After five minutes, the introduction of a solution of diamond blue with formaldehyde 10% in a volume of 2.0 ml.

5) Spinal cord extraction.

6) The study of macro, coloring and sections.

An example of a specific way to create a model

During the testing of the ischemia model, 6 laboratory animals were used. In three rats, paralysis of the lower extremities arose on the first day. By the third day, paresis and paralysis in the lower extremities were observed in all animals of this group. As a result, in all laboratory animals on a macrodrug, staining of the spinal column and spinal cord was higher than the level of manipulation.

Features of the invention, distinctive from the prototype

Proposed as an invention model for the creation of spinal cord ischemia:

- lack of ligation and transection of the abdominal part of the aorta,

- the introduction of drugs intraperitoneally,

- ligation of the inferior vena cava,

- venous overload of the lower extremities,

- increased venous pressure in the system of vertebral collaterals between the lower and upper vena cava,

- destruction of collaterals.

The beneficial effect of the invention

Obtaining persistent ischemia in laboratory animals, administering drugs intraperitoneally, reducing animal injuries during operations, the possibility of a longer observation. The absence of ischemia of the intestines and lower extremities, the lack of impaired blood supply to the mesenteric veins

Sources of information taken into account

1. Translational medicine, August 2014, pp. 40-45. - prototype.

2. "Guide for the care and use of laboratory animals" (publication of the National Institute of Health No. 85-23, USA).

3. “Guidelines for the experimental (preclinical) study of new pharmacological substances”, edited by R.U. Khabrieva (2005).

Claims (1)

A method for simulating spinal cord ischemia in laboratory animals, characterized in that Propofol is anesthetized, the abdominal part of the aorta and the inferior vena cava are isolated, ligatures are placed below the renal arteries, the collaterals are destroyed with a scalpel, the inferior vena cava is bandaged below the renal vessels, then remove ligatures from the place of their imposition.