兔缩窄性心包炎模型,疾病动物模型 z-bio 2021-03-17 249

　　(1) Breeding method The New Zealand rabbit weighs 1.5-2.0 kg, fixed the back, and uses 2% procaine for local infiltration anesthesia. A small incision is made in the center of the upper abdomen, and about 0.5 g of liver tissue is collected to check the moisture content of the liver. Then make a midline incision of about 2 cm near the sternum and left rib, push the rib cage muscle near the sternum to 1.5 cm, and pull the upper and lower ribs from the intercostal incision to both sides. Exposed the breastbone, bare pericardium. Use a No. 7 lumbar puncture needle to puncture the horizontal position under the thorax to the apex of the heart, and penetrate the pericardial cavity from the surface of the pericardium. Inject the inducer according to 1 ml/kg body weight (the inducer is prepared as a suspension of 4 g sterile talc, 1 g tetracycline powder and 20 ml 1.5% iodine tin). Two weeks after the inducer injection, the animals were sacrificed, the chest cavity was immediately opened, the left and right pleural effusions were measured, the pericardial thickening was observed, and the grade of the pericardial thickening was evaluated. Take two samples, myocardium and pericardium, for pathological examination. Open the abdominal cavity, measure the ascites, and take two liver tissue samples. One is used for pathological examination, and the other is used for water in liver tissue. The standard of pericardial adhesion and thickening: Grade 0: Normal pericardium: The pericardium is thin and transparent, and there is no adhesion between the pericardium and the myocardium. The vascular network on the surface of the myocardium is clearly visible through the pericardium. Grade 1: Thickening and whitening of the pericardium, with interspersed filiform adhesions between the pericardium and myocardium, and large blood vessels passing through the pericardium can be seen on the surface of the myocardium; Grade 2: Thickening of the pericardium, whitening and adhesion to the pericardial myocardium. You cannot see the blood vessels that pass through the pericardium, but you can see the pericardium. Level 3: Increase the pericardium. Its thickness becomes whiter, and the myocardium disappears through the pericardium. Measurement and calculation of liver water content: Before and 2 weeks after creating the model, take a piece of liver tissue with a size of 0.5 g, wash it with saline, absorb the water with filter paper, weigh it with an analytical balance, and place it. When a certain weight is reached for 72 hours in an oven at 60°C, the weight is the dry weight. Then calculate the following formula: liver water content=(dry weight of liver)/wet weight×100%, take samples of pericardium, myocardium and liver tissue, fix them in 10% formaldehyde solution, embed in paraffin, and slice. , HE staining, observe under an optical microscope.

　　(2) Features of the model This model is made by injecting an inducer from the chest under local anesthesia. It is simple and easy to implement, has little interference to the animal's body, and does not require special postoperative care. The judgment of experimental animals for pericardial thickening has also been improved. In conventional methods, pathological sections of pericardial specimens are prepared and observed and compared under a microscope. However, due to differences in specimen selection and the observer’s understanding, there is no uniform standard for determining pericardial thickening. This test uses the rabbit's normal pericardial transparency to assess the thickening of the pericardium relative to the myocardium and its superficial blood vessels. Pericardial thickening is relatively quantitative and determined by the judgment of pericardial thickness. A relatively clear purpose. index. In addition, many of the animal sources and low-cost rabbits used in this model are experimental animals, which are easy to operate, fast and useful for large-scale replication of the model. It provides a new animal model for further study of constrictive pericarditis.

　　(3) Comparative medicine Clinical pericardial contraction can limit the expansion and contraction of myocardium, block venous return, systemic venous congestion, insufficient arterial blood supply, and ischemia and hypoxia of key organs. Two weeks after the inducer was injected into the pericardial cavity, the model showed signs of lung and systemic congestion in the animal, such as thickening of the pericardium, rapid breathing, pleural effusion, ascites and increased liver water content. I showed my performance. These symptoms are similar to the clinical symptoms of constrictive pericarditis. Animal anatomy also shows that rabbits are different from dogs, sheep and other animals. The pleural reflex in the pleural cavity is very similar to humans. There is approximately 1 cm2 of exposed pleural area in front of the pericardium.