疾病动物模型,心肌缺血模型 z-bio 2021-03-17 307

　　(1) Replication method Male Wistar rats, weighing 300-400g. Wire: 0.36 mm in diameter, can be reused. The wire can be shortened to 30 cm to improve operability. The perfusion catheter was shortened to 20 cm and used as a cardiac catheter to cause myocardial infarction. The animals were anesthetized by intraperitoneal injection of 3% pentobarbital at a dose of 50 mg/kg. Before intubation, preventive doses of lidocaine (2 mg/kg, ip) and heparin (200 U/kg, sc) were given to reduce ventricular fibrillation and thrombosis. The back of the animal is fixed, and the neck is incised in the middle. Separate the right common carotid artery and ligate the distal end. A24 hypodermic needle punctures the common carotid artery. The criterion for successful puncture is the flow of arterial blood from the inner needle. Pulling out the inner needle allows the outer tube to slowly enter the carotid artery. Ligate the bare carotid artery with silk thread to prevent blood from flowing out. Under fluorescence induction, the cardiac catheter (J-shaped tip) enters the left coronary artery through the cannula and ascending aorta. The wire is gently connected to the bottom of the left coronary artery, and the wire is rotated counterclockwise to the left. Coronary artery (LCA). The guide wire rotates clockwise at the root of the right coronary artery and enters the right coronary artery (RCA). After the reed enters the coronary artery, the reed will slowly advance until the animal's ECG shows an elevated ST segment. Since the weight of the animal in this experiment is heavier, the thickness of the coronary artery corresponds to the outer diameter of the wire. Therefore, a few millimeters of thread entering the coronary artery will completely block the blood supply downstream and cause transmural ischemia. The lead was removed after 60 seconds of coronary artery occlusion. At the end of the test, the overtube was removed, the carotid artery wound was completely sealed, and then the skin incision was sutured. Transient myocardial ischemia occurred in both the left and right coronary arteries. After the lead enters the LCA, the ST segment rises significantly from V1 to V6, indicating that there is transmural myocardial ischemia in the left ventricle. After entering RCA, ST elevation appears in II, II, aVf, V1 and V2.

　　(2) Model characteristics The transient myocardial ischemia model is established based on the mini-intubation technique rather than thoracotomy. This greatly reduces surgical complications, such as pneumothorax and infection, and reduces the size of the animal. This model is much larger than the open-chest method and requires more experimental equipment.

　　(3) Comparing the suture methods of rats to create a myocardial infarction model can produce transient myocardial ischemia in animals with less trauma than coronary artery ligation. Second, the model can iteratively create a consistent ischemia model that does not damage blood vessels in the same coronary artery region of the animal. Finally, the ischemia model caused by the guide wire 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 very small and can simulate the recovery process after repeated myocardial ischemia.