动物造模 z-bo 2022-02-03 386

　　Rabbits, pigs, rats, chickens, pigeons, monkeys and dogs are often used. There are several commonly used methods of copying.

　　1. High cholesterol and high fat feeding method: This is a common method with low mortality and long-term observation, but it takes time. Rabbits, pigeons, chickens, etc. usually have obvious hyperlipidemia after a few weeks of eating, and early atherosclerotic lesions will form a few months later. The formation of rats, mice and dogs is more difficult, but egg yolk, cholic acid and lard can be added to the diet to speed it up. Methionine, propylthiouracil, methionine, amphetamine, vitamin D, nicotine or sucrose can also be added to a high-fat diet to promote the formation of lesions.

　　Specific reproductive method: Rabbit provocative model: weighs about 2 kg, and has 0.3 g of cholesterol per day. After 4 months, aortic hardening plaques are visible to the naked eye. If the daily dose is increased to 0.5 g, plaque will appear after 3 months of obstruction; if it is increased to 1 g per day, it can be reduced to 2 months. Add 15% egg yolk powder, 0.5% cholesterol, and 5% lard into the feed. After 3 weeks, the cholesterol in the feed will be deducted and the feeding will continue for 3 weeks. The incidence of aortic plaque can reach 100%. It grows to 2000mg%. Rat-induced model: 1-4% cholesterol, 10% lard, 0.2% methylthiouracil, 86-89% basic diet, 7-10 days or 10% protein powder, 5% lard, With 0.5% bile salts and 85% basic diet, hypercholesterolemia will develop after 7 days. Mouse-induced model: male mice are fed a high-fat diet of 1% cholesterol and 10% lard, and serum cholesterol increases to 343±15 mg after 7 days; if 0.3% cholic acid is added to the diet, it is 7 days . Continue feeding, serum cholesterol can be as high as 530±36 mg%. Use chickens and pigeons as a model: taste the chicken in a 4-8 week old lake, add 1-2% cholesterol or 15% egg yolk powder to the feed, and add 5-10% lard within 6-10 weeks. The incidence of thoracic aortic plaque reaches 100%, up to 1000-4000 mg%, after which blood cholesterol rises. Pigeons are fed with cholesterol of 3 g/kg/day and 0.1 g of methylthiouracil can produce more animal plaques.

　　2. Immunological method: Injecting white rat aortic homogenate into rabbits may increase blood cholesterol, β-lipoprotein and triglycerides. 4 injections every 17 days, the dose is 10 ml/kg/dose. The intimal injury rate was 88%, and the coronary arteries also had atherosclerotic lesions. At the same time, feeding on a high-cholesterol diet makes the lesion more obvious. Rabbits fed a drink containing 1% cholesterol and an intravenous injection of 250 mg/kg bovine serum albumin may accelerate the formation of intimal artery disease caused by a high-cholesterol diet.

　　3. Catecholamine injection method: Inject 1 mg of norepinephrine into rabbits every day for 30 minutes. One method is to instill for 15 minutes, let it stand for 5 minutes, and then inject it for 15 minutes. Another option is to instill for 5 minutes and then rest for 5 minutes each. The above two methods last for two weeks and can cause aortic disease, indicating that the elastic fibers in the middle layer of the blood vessel wall are stretched, split or destroyed, and necrosis and calcification appear in the disease.

　　4. Homocysteine injection method: dl-homocysteine thiolactone (dl-homocysteine thiolactone) 20-25mg/kg/day (1mg/ml in 5% glucose solution) within about 25 days Twenty subcutaneous injections resulted in atherosclerosis. Both adult and young rabbits showed typical atherosclerotic lesions. Coronary artery lumen stenosis, the matrix shows the proliferation of intimal muscle cells of the artery wall, fibrotic tissue proliferation, elastic fiber breakage, thickening of the vessel wall, and piles of granular and fibrous discoloration substances.. When 20% cholesterol is added to the diet, When homocysteine thiolactone was injected at the same time, all animals showed obvious atherosclerotic lesions.

　　5. Surfactant infusion: Intraperitoneal injection of Triton WR1339 300mg/kg in rats can increase serum cholesterol by 3-4 after 9 hours, and serum cholesterol in male rats is still at the normal level after 20 hours. 4 times. However, the serum cholesterol level of female rats is about 6 times; about 24 hours after taking the drug, the lipid-elevating effect reaches its peak and returns to normal within about 48 hours. Among them, the increase in triglycerides was the strongest, followed by phospholipids, free fatty acids and free cholesterol, which did not affect cholesterol lipids.

　　6. Cholesterol fat emulsion intravenous injection method: Dissolve 3 g of cholesterol and lard under electromagnetic heating and stirring, add Tween-803 g and stir well, then slowly add 5 ml of propylene glycol and boiling water mixture to complete stirring emulsification and formation. 100ml, after suction filtration, confirmed under the microscope, the emulsion particles are uniform and can be used in the range of 7-8μm or less. Injecting 5 ml/kg intravenously into rabbit ears immediately increases plasma cholesterol and triglycerides. The total cholesterol is increased by six times than normal. The free cholesterol is mainly free cholesterol, and the ratio of free cholesterol to total cholesterol is 90%. Thereafter, the total plasma cholesterol gradually decreased, a low peak appeared at 6 hours, and thereafter it increased slightly. After 3-4 days, the ratio of free cholesterol to total cholesterol is close to the normal level (about 40%), and plasma cholesterol returns to normal after 7-14 days.

　　7. Young rat method: Due to the high fat content in milk and abnormal thyroid function, the serum cholesterol of young mice is usually 2-3 times higher than that of adult mice. Using a normal diet instead of breastfeeding can quickly reduce serum cholesterol to the level of normal adult rats. We conducted an experiment in which 30 to 50 g of white mice were breast-fed for 25 days by selecting male and female mice that were not breast-fed, to observe the effect of the drug in lowering cholesterol and compare it with a control group. Do it. It is generally believed that this type of hypercholesterolemia is very sensitive to thyroxine and its derivatives, but not sensitive to certain cholesterol biosynthesis inhibitors.

　　8. Alternatives: There are many factors that can lead to hyperlipidemia and atherosclerosis. For example, cerebral ischemia in animals, electrical stimulation of the central nervous system, high stress conditions, exposure to high levels of estrogen and carbon monoxide in birds, and balloon damage to the endothelial cells of the arterial wall.

　　Characteristics of various hyperlipidemia and atherosclerosis animal models: In addition to voles and hamsters, ordinary warm-blooded animals can form atherosclerotic plaque lesions as long as they use appropriate methods.

　　⑴ Rabbits are the earliest animals used, and are often used to create hyperlipidemia and atherosclerosis models. The absorption rate of exogenous cholesterol is very high, up to 75-95%, and only 40% in rats. Its ability to clear hyperlipidemia is weak and lasts for 3 to 4 days after intravenous injection of cholesterol. The dog was in the middle twelve hours. As long as you feed the rabbit a high cholesterol diet, no other factors are needed. Obvious atherosclerosis develops within 3 to 4 months, similar to diseases that occur in humans, and it is convenient to collect blood for testing. However, it also has some disadvantages, including the need to reach high levels of serum cholesterol to form plaque. At present, internal organs are prone to lipid deposition, have a short life span, low resistance, and are prone to death from secondary infections. In addition, rabbits are herbivores, and their ester metabolism is completely different from that of humans.

　　[2] Experiments show that coronary artery disease mainly occurs in the small arteries of the heart, while humans mainly occur in the large branches of the coronary arteries. White mice use white mice to establish hyperlipidemia and atherosclerosis models. This has the advantages of convenient feeding, strong tolerance and similar eating habits. The resulting pathological changes are similar to the early stages of humans, and it is not easy to form late-stage lesions similar to humans, and it is easier to form thrombus. The average serum cholesterol of normal rats was 92.67±1.87 mg%. It is not easy to increase serum cholesterol and atherosclerosis only by increasing the cholesterol in the feed. In order to increase the absorption of cholesterol, it is necessary to add cholic acid to the feed at the same time, which can cause hypercholesterolemia drugs, such as adding antithyroid drugs; it can further increase serum cholesterol..

　　(3) The advantage of using white mice to create experimental models for white mice is to facilitate the breeding and storage of drugs, but it is inconvenient to collect blood and cannot be dynamically observed. This is difficult and rarely used.

　　⑷Chicken is an omnivorous animal, and its food type is similar to that of humans. Therefore, it is only necessary to add cholesterol to the normal feed to form atheroma. The lesions develop rapidly and may be accompanied by plaque calcification and ulcers. Doves are like chickens. The summary is simple. [5] Adding cholesterol to the diet can lead to the formation of hardened plaques in the aorta, which can lead to myocardial infarction. Due to different breeds of pigeons, the nature of atherosclerotic plaques may be very different, which may be due to differences in lipase activity between individuals. The condition of monkeys is very similar to that of humans, and regardless of normal blood lipids, the nature and location of atherosclerotic lesions, clinical symptoms and the therapeutic effects of various drugs, monkeys are very similar to humans. However, further studies have shown that different species have different sensitivity to atherosclerosis.

　　[6] Rhesus monkeys are generally considered ideal. After a high-fat diet for 1-3 months, serum cholesterol levels can reach 300-600 mg%, and atherosclerosis can be seen, which may cause myocardial infarction. The location of atherosclerotic lesions is not only in the aorta, but also in the coronary arteries, cerebral arteries, renal arteries and femoral arteries.

　　⑺Pig may be an ideal animal model for studying atherosclerosis. This is because some older pigs will develop atherosclerotic lesions in the arteries, coronary arteries and brain serum after being left by humans. Very similar to human lesions. Feeding only high cholesterol and high fat diets can cause experimental atherosclerosis in a relatively short period of time (9-18 months). In addition, probe puncture and high-cholesterol and high-fat diets can quickly cause progressive aortic and coronary atherosclerosis. Other benefits of the pig model include human-like anatomy and physiology, similar arterial structure, number of available confirmed breeds, multiple births, multiple litters and omnivores. This size is sufficient for various surgical operations and clinical evaluations. use. Pigs are also particularly suitable for studying the relationship between stressors and atherosclerosis. The disadvantage of the pig model is that it takes a certain amount of money to raise it, and the artificial change of atherosclerosis requires some changes in lipid metabolism or the basis of arterial damage.