疾病动物模型,失常模型,心肌缺血再灌 z-bio 2021-03-18 406

　　(1) Replication method Male rats weighing 250-450g are anesthetized by intraperitoneal injection with 25% urethane at a dose of 1.2-1.5g/kg body weight. The animal is fixed on the operating table in a supine position, and needle electrodes are inserted into the large The mouse’s limbs were subcutaneously connected to the ECG machine and ECG oscilloscope, and a section of lead II of the normal ECG was recorded. The skin was cut in the middle of the neck, the trachea was separated for tracheal intubation, and the artificial respirator was connected for artificial respiration. The breathing ratio was adjusted to 1:2; the breathing rate was 60 times/min, and the tidal volume was 60ml/kg body weight. Open the chest between the 3rd and 4th intercostals to expose the heart and cut the pericardium. A needle was inserted about 2 mm from the beginning of the anterior descending branch of the left coronary artery of the heart and a No. 1 silk thread was placed. After stabilizing for 10 minutes, a plastic hose with a length of 1 cm and an inner diameter of 3 mm was ligated together with the artery. After that, the electrocardiogram was recorded every minute, and after continuous recording for 30 minutes, the silk thread was cut along the plastic hose and reperfused. The electrocardiogram was recorded once every minute for 40 minutes to observe the occurrence of arrhythmia in rats. Arrhythmia may occur immediately after the recovery of coronary perfusion, mainly manifested as asphyxiant premature beats, ventricular tachycardia, ventricular fibrillation, and atrioventricular block. The highest incidence occurred within 15 minutes after reperfusion.

　　(2) Model characteristics Ischemia-reperfusion injury mainly studies the protective effect of drugs on myocardial cells during hypoxia-reoxygenation, and can be used to study whether drugs can treat arrhythmia caused by ischemia-reperfusion injury. The model created by this method has the advantages of simple operation and high success rate; the disadvantage is that the rat

　　The anterior descending branch of the coronary artery has a large variation, and the ligation site is difficult to be in the same position every time, resulting in large variability in the test.

　　(3) Comparative medicine Myocardial ischemia-reperfusion injury manifests as perfusion arrhythmia, myocardial stunning, ligation damage and intramyocardial hemorrhage. The mechanism is mainly two factors, free radicals and intracellular calcium overload. Free radicals generated during ischemia and reperfusion can react with lipids, nucleic acids, etc. in the aerobic environment during reperfusion, causing aggravation of biofilm damage and causing further intracellular Ca2+ overload, leading to severe heart rhythm Abnormal.