动物造模,药效评价,心肌病 z-bio 2024-08-07 375

　　1. Experimental animals commonly used are rats weighing 100-200g, regardless of gender.

　　2. Experimental methods require timely recording of electrocardiograms. Rats can be lightly anesthetized with ether beforehand, with their heads and limbs fixed in a supine position, and electrocardiograms recorded using chest and II leads. Alternatively, medication can be administered first, usually using isoproterenol aqueous solution or demethylated epinephrine, and then regular observation of electrocardiogram changes can be conducted. Subcutaneous injection (or intraperitoneal injection) of isoproterenol aqueous solution into the inner thigh of the hind limbs of rats, once a day, at a dose of 1-10mg/kg each time, for 2 consecutive days. Electrocardiograms can be recorded at 1, 5, 10, 30, 45... minutes after each injection to observe changes in acute myocardial ischemia.

　　3. Reference results: Generally, a clearly defined myocardial necrosis lesion is formed on the 3rd to 4th day after the first injection. On the 7th day, there is a significant increase in fibroblasts in the lesion, and it enters the myocardial fibrosis stage after the 3rd week. 48 hours after the last injection, a cardiac pathological examination was performed, and the vast majority of animals could see clearly defined myocardial necrosis lesions. Some of these lesions are necrotic empty spaces with few clean cells; More often, it is a multicellular lesion with strong macrophage response and vigorous fibroblast proliferation. The necrotic lesions are mainly distributed in the left ventricular wall and interventricular septum, especially near the apex of the heart. Larger lesions are usually distributed in the papillary muscles and inner myocardium, while lesions in the middle and outer myocardium are generally smaller. Lesions in the inner layer of the heart wall often retain 1-2 non necrotic myocardial cells closely beneath the endocardium, but this retention is not as complete as typical myocardial infarction, and some areas of necrosis can directly reach the endocardium. Myocardial necrosis lesions are often distributed around small branches of the coronary artery. The extent of myocardial necrosis or fibrosis can be measured and observed using an image analysis system, and myocardial fibrosis can also be detected for collagen content.