动物造模,心肌缺血 z-bo 2020-08-05 596

　　(1) Replication method Male Wistar rats weighing 300-400 g. Lead wire: 0.36mm in diameter, which can be reused in the test. For easy operation, the lead wire can be shortened to 30cm. The perfusion catheter was shortened to 20cm, which caused myocardial infarction as a cardiac catheter. Animals were anesthetized by intraperitoneal injection of 3% pentobarbital at a dose of 50 mg/kg. Before intubation, preventive doses of lidocaine (2mg/kg, ip) and heparin (200U/kg, sc) were given to reduce the formation of ventricular fibrillation and thrombus. The animal was fixed on its back with a midline incision in the neck. Separate the right common carotid artery and ligate the distal end. A24-size hypodermic needle, puncture the common carotid artery. The standard for successful puncture is: arterial blood flows out from the inner needle. When the inner needle is removed, the outer sleeve can slowly enter the carotid artery. The exposed carotid artery was ligated with silk thread to prevent blood from flowing out. The cardiac catheter (with a j-shaped tip) enters the left coronary artery through the ascending aorta through the cannula under fluorescent guidance. The wire is gently attached to the root of the left coronary artery, and the wire is rotated counterclockwise into the left coronary artery (LCA). The wire is rotated clockwise at the root of the right coronary artery and enters the right coronary artery (RCA). Once the lead enters the coronary artery, the lead slowly advances until the animal's ECG shows an elevated ST segment. The weight of the animals in this experiment is large, so that the thickness of the coronary arteries is equivalent to the outer diameter of the wire. Therefore, a few millimeters of the wire entering the coronary artery can completely block the blood supply downstream, resulting in transmural myocardial ischemia. The lead was removed 60 seconds after the coronary artery was blocked. At the end of the test, the overtube was removed, and after the carotid artery wound was completely closed, the skin incision was sutured. Transient myocardial ischemia occurred in both the right and left coronary arteries. When the lead enters the LCA, the ST segment rises significantly from V1 to V6, indicating that the left ventricle is transmural myocardial ischemia. After entering RCA, S-T segment elevation appeared in II, II, aVf, V1 and V2.

　　(2) Features of the model A transient myocardial ischemia model is established based on a small intubation technique, instead of thoracotomy, which greatly reduces surgical complications such as pneumothorax, infection, and animal deaths However, the difficulty of the model is significantly greater than that of the open-chest method, and the requirements for experimental equipment are high.

　　(3) Comparative medicine The rat suture method is used to create a myocardial infarction model, which can create transient myocardial ischemia in small animals that is less traumatic than coronary artery ligation. Secondly, this model can repeatedly create a consistent ischemic model that does not damage blood vessels in the same coronary artery area on the animal. Finally, the ischemia model caused by this guidewire can also be improved into an irreversible myocardial infarction model (thromboxane is injected into the coronary artery through a catheter to form a thrombus and block the blood vessel). The damage to blood vessels is small, and it can simulate the process of recovery after repeated myocardial ischemia.