疾病动物模型,心肌梗死模型 z-bio 2021-03-17 405

　　(1) Breeding method After measuring the body weight, the experimental dog was anesthetized by intravenous administration of 3% sodium pentobarbital 30 mg/kg and inserted into the trachea. Fix the animal in the right decubitus position, separate the femoral artery and vein, measure the peripheral arterial pressure, give the test sample, and add anesthetic [3% sodium pentobarbital 10 ml, 500 ml normal saline, 5 ml / (kg) . Isolate the right jugular vein cannula for intravenous infusion of heparin. Open the chest from the 4th and 5th intercostal space, cut open the bag to expose the heart, separate the left circumflex branch (LCX) from the root to the first main branch, and ligate the remaining small branches. The length of the separation is about 2 cm, and a suitable electromagnetic hook is installed. The flow meter probe (approximately 2 mm) continuously records the blood flow of the left circumflex branch. Pass the thin silk thread through the LCX, lift the silk thread to stop the blood flow for 20 seconds, and then observe and record the changes in blood flow. Lower the silk thread to completely fill with blood, and use this flow rate as the peak flow rate. Place some small silver clips on the LCX and adjust the silver clips to reduce blood flow to approximately 30% of the peak flow (approximately 8 ml/min in this test). Once the flow is relatively stable, electrical stimulation can be started. The electrical stimulation needle is made of stainless steel, and the tip of the electrode penetrates the wall of the LCX blood vessel, extends into the lumen, and is fixed so that the tip is in close contact with the artery intima. Continue the electrical stimulation of DC 150μA until the LCX blood flow becomes 0 for 3 minutes. The electrical stimulation time is 15 minutes or longer, and this time is recorded as the time when blood flow obstruction occurs. When selecting samples, the re-ventilation time observed after administration refers to the time from the start of administration to the time the LCX flow rate before electrical stimulation returns to 1/3 of the flow rate. The re-blocking time refers to the LCX flow rate from the re-opening time to 0 o'clock again. At the end of the experiment, the animals were sacrificed, the LCX section was cut long enough and dissected, the thrombus was taken out and its wet weight was weighed.

　　(2) Model features This model requires thoracotomy, which is difficult to operate, but easy to identify. This model has a high success rate and good stability. It is mainly used for the screening and pharmacodynamic evaluation of coronary thrombolytic drugs. .. Judging the occlusion and recanalization of coronary arteries by observing the blood flow of the coronary arteries, the indicators are objective. During the modeling process, animals are prone to ventricular arrhythmia, which can cause ventricular fibrillation. This requires monitoring and defibrillation.

　　(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. This model uses thoracotomy to stimulate the left circumflex coronary artery in an acute myocardial infarction model with similar clinical causes. However, thoracotomy itself will cause a series of pathophysiological changes in animals. Although this is partly different from clinical acute myocardial infarction, the results of myocardial pathology and electrocardiogram changes are similar to those of patients with clinical acute myocardial infarction.