动物造模,心肌梗死后心力衰竭模型 z-bio 2023-10-16 771

　　1. Animal modeling material: Healthy male SD rats, weighing (200 ± 30) g; Medications: Ether, penicillin.

　　2. Method of modeling: After inhalation anesthesia with ether, fix it on a small operating table, remove hair, disinfect with 75% alcohol and iodine tincture, cut the skin at the midline of the clavicle, and use hemostatic forceps to blunt open the chest tightly against the left edge of the sternum between the 3rd and 4th ribs. At the same time, separate the pericardium, and use your thumb and index finger to press upwards to quickly eject the heart, flipping it slightly inward, Find the anterior descending branch of the left coronary artery slightly 1-2 mm below the junction between the left atrial appendage and the pulmonary artery cone, and suture it with silk thread. It can be seen that the anterior wall of the heart immediately turns purple. Then, quickly place the heart back in place, close the chest, and press the chest to restore autonomous breathing in the animal. After surgery, penicillin was administered intraperitoneally to combat infection. Body surface electrocardiogram was recorded before and after surgery. The occurrence of arcuate upward elevation in the ST segment of lead 2 is a sign of successful coronary artery ligation. Indoor breeding, regular lighting, free eating and drinking, and surrounding the breeding area. Set up a sham surgery group, except for the absence of coronary artery ligation, all other steps are the same.

　　3. Modeling principle: Ligating the coronary artery causes myocardial infarction and leads to heart failure.

　　4. Changes after modeling: Compared with the sham surgery group, the model group rats had poor mental state, less activity and food intake, and immediately after ligation, there were QRS complex and/or ST-T changes in the electrocardiogram, some of which showed arrhythmias. The electrocardiogram of the sham surgery group showed no abnormal changes.

　　Four weeks after surgery, animal hemodynamic parameters were measured. The absolute values of the maximum rate of left ventricular pressure increase (+dp/dt max) and the maximum rate of left ventricular pressure decrease (- dp/dt max) in the model group were lower than those in the sham surgery group [+dp/dt max: sham surgery group (910.04 ± 116.64) kPa/s, model group (783.0 ± 119.7) kPa/s; - dp/dt max: sham surgery group (750.08 ± 95.31) kPa/s, model group (638.64 ± 98.11) kPa/s], LVEDP was higher than that of the sham surgery group [sham surgery group (0.45 ± 0.19) kPa, model group (1.13 ± 0.28) kPa].

　　5. Precautions: After the concentration of ether in the anesthesia container stabilizes, the animal can be placed in it. After losing consciousness and muscle relaxation, it can be left for about 30 seconds for surgery, which can basically continue until the end of the surgery.

　　Using the cooperation of two surgeons, one operator closely adheres to the left edge of the sternum and separates the ribs perpendicular to the intercostal space, while the assistant separates them parallel to the intercostal space. At this time, the heart quickly pops out and seals the incision under the compression of the left thumb and index finger. After proficiency, the entire operation process from thoracotomy to suturing can be completed within 35-40 seconds.

　　Ligation site: Select a location 1-2 mm below the junction between the left atrial appendage and the pulmonary artery cone for ligation. The infarct area is mostly around 40%, which is suitable for chronic heart failure. Excessive ligation can cause acute death in animals, while low ligation can result in small infarct size and less likely to cause heart failure.

　　Nursing: After animal anesthesia, there is a lot of secretions. You can use a 20ml syringe and infusion tube to make a self-made sputum aspirator to extract the secretions