疾病动物模型,急性心肌梗死模型 z-bio 2021-03-17 464

　　(1) The animals used for the replication method are rats, dogs and rabbits. Here, we will introduce in detail how to use dogs to create an acute myocardial infarction model. The modeling methods of other animals are basically the same as that of dogs. Inject 30 mg/kg of pentobarbital 3% sodium intravenously for intravenous anesthesia, and at the same time insert a tracheal intubation through the mouth for anesthesia, and connect the ventilator. The frequency is 30 beats/minute, the respiratory ratio is 1.5:1, and the respiratory volume is adjusted to a positive respiratory pressure of 0.98 kPa (10 cmH2O). Place the animal on the right side, fix it on the operating table, separate the femoral vein at the right groin, and insert a catheter for injection. Make a midline incision in the upper abdomen, carefully find the duodenum, perform a suture, insert a tube 3 cm from the pylorus, and connect the medicated tee. Open the thoracic cavity between the third and fourth intercostals of the left chest wall, open the thoracic cavity with a dilator, incise a 2 cm pericardium from the renal nerve in the direction of the nerve, and suture the pericardial line completely to the chest wall. Do it. Show your heart. Loosen the coronary artery between the second and third branches, screw in a 2 under it, and suture the four corners of the 30 external electrodes formed on the surface of the heart with a complete cardiovascular suture needle according to the literature. . The electrode spacing is 8 mm, and normal limbs are tracked simultaneously. Compressed limb aVR, aVL and aVF leads with I, II, and III leads, and a 30-minute electrocardiogram is depicted on the surface. The ECG can be calibrated by tracking the limbs and reeds. ? 8 mm/mv, and the epicardial potential map is calibrated to 1 mm/mv. The recording paper speed is 25 mm/sec. The ligation started 30 minutes after the operation. Harris' two-step ligation method: two minutes before the first ligation, 5 mg/kg lidocaine is injected intravenously from the femoral vein, and a 6-gauge needle is added during the ligation and removed after the ligation. 30 minutes after the first ligation. Perform the second ligation. After the second ligation, the changes of the epicardial ECG were continuously observed, and the ST-segment displacement was determined to be the sum of the ST-segment displacement (∑-ST) and the number of ECG leads (N-ST) above 2mv. In about 3 hours at the expense of the animal, the heart was quickly excised, the atrium and the right ventricle were cut open, placed in the refrigerator for 1 hour to quickly freeze, and then the ventricle was cut into 5 slices of the same thickness. Below the parallel line of the coronary sulcus, I disconnected. Add 0.1% nitrotetrazole to the coronal groove and shake it for 10 minutes in a blue (N-BT) solution in a constant temperature water bath at 37°C for dyeing. Normal myocardium is stained dark blue, while infarcted myocardium is not stained bright red. Track, scan and use Osiris software to calculate the ratio of infarct area to left ventricular area. Before coronary artery ligation and 3 hours after administration, 3 ml of right ventricular blood was collected and centrifuged at 3000/min for 15 minutes to quickly freeze the serum. During the experiment, lactate dehydrogenase (LDH) and creatine kinase (CK) were measured.

　　(2) Model features The acute myocardial infarction model caused by thoracotomy and ligation of the left anterior descending artery is difficult to operate. Animals are prone to ventricular arrhythmia and cause ventricular fibrillation. Monitor and defibrillate as needed. Lidocaine is given before the coronary arteries as needed to prevent the development of severe arrhythmia. The trauma is large, the success rate is high, the positioning model is stable, and the animal cost is high.

　　(3) Comparative medical clinical research is caused by almost all myocardial infarctions, especially coronary atherosclerosis in elderly patients, sometimes caused by coronary thromboembolism, inflammation and congenital malformations. In autopsy cases of acute myocardial infarction, 85%-95% of coronary arteries are found to have thromboangiitis obliterans. Based on coronary atherosclerosis, when bleeding or persistent vasospasm or thrombosis occurs in or under the atherosclerotic plaque, the coronary arteries will be completely occluded, causing myocardial infarction. There is a certain gap between the acute myocardial infarction model caused by thoracotomy and ligation of the left anterior descending artery and the clinical cause. The thoracotomy itself will cause a series of pathophysiological changes in animals, but the pathology and electrocardiogram changes of myocardial infarction are similar and clinically similar.