动物模型,心肌梗死 z-bo 2020-08-12 441

　　1. Experimental animals Generally, male rats weighing about 300 g are used.

　　2. Model preparation method Intraperitoneal anesthesia (50mg/kg) with 5% pentobarbital sodium, fixed on the operating table supine. Touch the intercostal space where the apex of the rat is most pulsating, cut the skin and intercostal muscles, squeeze out the heart, find the anterior descending branch at the junction of the pulmonary artery cone and the left atrial appendage, ligate it with silk thread 2mm from the root, and quickly return the heart The thoracic cavity, and quickly squeeze the thoracic cage until the animal resumes spontaneous breathing, and suture the chest wall muscles and skin. (Tips: The left coronary artery originates from the aorta and is close to the left edge of the pulmonary sinus. It runs between the pulmonary sinus and the left atrial appendage. Head-to-tail oblique walking 2~3mm, then branch, buried in the subepicardial myocardium, usually not visible. Therefore, when ligating, thread the silk thread through the pulmonary sinus and connect it from the pulmonary sinus to the end of the left atrial appendage at a distance of 2mm from the pulmonary valve. Pass out the middle of the thread and suture about 5mm wide myocardium to ensure that the artery is ligated. The ligation should be fast to minimize the time the heart is placed outside the chest).

　　3. Evaluation of research results

　　(1) Heart function evaluation: It can record heart rate, blood pressure, left ventricular pressure and isovolumic systolic pressure differential (dp/dt) through carotid cannulation and connected to a multi-channel physiological recorder. It is mostly used in acute experiments. Some laboratories can provide special ultrasound instruments for small animals to detect heart function, which can ensure the needs of chronic experiments.

　　(2) Gross pathology: The area of infarcted myocardium can be assessed semi-quantitatively, and tetrazolium blue (TTC) staining is commonly used. Before the animals were sacrificed, 0.5% Evans blue solution was injected through an intravenous cannula. The normal myocardium was stained blue, and the infarcted and ischemic myocardium were not stained. The animal was sacrificed, the heart was quickly removed, the water was absorbed with filter paper, and it was placed in a refrigerator at -20°C for 20 minutes and then taken out. The vertical long axis of the left ventricle was cut into 2 to 3 mm cross-sections, and then immersed in 2% TTC solution. React in a 37°C water bath for 30 minutes. The ischemic myocardium is stained brick red, and the infarcted myocardium is not stained. Weigh each myocardial slice, take a picture of the slice, analyze the color of each slice with an image analysis system, and express it as the percentage of the infarct area in the total area of the left ventricle, and find the weighted average of all slices.

　　(3) Histology: According to research needs, select immunohistochemistry, immunofluorescence and other methods to detect target substances.