白内障,动物造模 z-bo 2022-02-24 569

　　This type of cataract model uses various drugs to affect the metabolism of the lens to form cataracts. Commonly used are D-galactose, sodium selenate, naphthalene, glucocorticoids, and the less commonly used bleomycin, pinyangmycin and baiyao. , Cysteamine, xylazine, etc.

　　1, D-galactose-induced cataract animal model

　　[Modeling mechanism] Excessive D-galactose is metabolized in the lens into galactitol. Galactose cannot penetrate the lens capsule and accumulate in the lens, resulting in osmotic pressure causing the lens. Lens fibrous edema, necrosis and cataract formation. [Modeling method] According to the method of ingesting galactose, it can be divided into three types.

　　: (1) High-galactose diet: 50% to 60% galactose to weaned puppies can cause cataracts. H (Holtzmann) rats usually require the shortest time, followed by RW (Rochestercolony Wistar) rats and CN (Carworth Farmeloon) the longest. Some people use guinea pigs instead of mice. Guinea pigs are closer to the formation of human lactose cataracts, because neither guinea pigs nor humans can synthesize their own daily vitamin C, and the onset of cataracts can be delayed due to the antioxidant effect of vitamin C. Choose 300 grams of adult guinea pigs, whose diet does not contain vitamin C and 10% galactose. These are usually modeled within 9 days.

　　(2) Intraperitoneal injection of galactose: intraperitoneal injection of 50% galactose solution (total 15-30 g/kg), 3 days after injection, small vesicles appear in the equator of the rat lens, the longest is about 17 day. The lens is completely cloudy. At injection doses higher than 30 g/kg, all test mice will have macroscopically complete lens opacities, but the mortality rate of test mice is higher. When it is lower than 15g/kg, the disease develops later and the model becomes unstable. (3) After galactose globule injection: twice a day or twice a week, use a fixed monocular eye to inject 0.2 ml of 0.4% galactose saline into the guinea pig. Cataract formation is slow and can be controlled by two injections a week. There are clear boundaries between the various stages of cataract formation. If you inject 0 times a day, the lens will soon become completely cloudy.

　　[Model characteristics] After receiving the galactose diet, the lens began to appear in the form of peripheral vesicles on the 4th day, and gradually expanded to the center; the 7th day was the vesicular phase; the 10th day was the obvious turbidity of the cortex; typical began to appear Nuclear opacity. On the 14th day, the main feature is that the center of the lens nucleus is dark and milky white, and all the remaining animals on the 19th day have cataracts. When we enter the mature stage, the naked eye can see the milky reflection of the pupil, and the central area becomes the darkest. About 30 days after stopping feeding galactose, it began to reverse. After seeing a circular translucent area on the equator, the translucent area gradually expanded to the central area and became more transparent, and the cortex became more transparent after 45 days. Be basically transparent. In the slit lamp inspection, fibrous opaque areas are scattered in the transparent areas, but after 60 days of inspection, only the opaque areas of the needle-shaped nuclei remain. Model evaluation and application In short, various methods of feeding galactose to laboratory animals may cause cataracts. Among these methods, the high galactose diet is the simplest method, but the results are slow and costly. The result after the ball is injected with less medicine is very fast, but the operation is complicated and there is a big gap between the physiological conditions. Intraperitoneal injection is better than oral or intra-ball injection because of its low dose and easy operation, and the results show faster and closer to physiological conditions. However, the disadvantage of intraperitoneal injection of D-galactose is the high mortality rate of the model. This may be because D-galactose causes hypertonicity of abdominal tissues, dehydration and desalination of organs and tissue cells, organ dysfunction, dysfunction and death. .. The pathological process of galactose cataract formation is basically the same as that of diabetic cataract, and it is mainly used for the research of diabetic cataract.