动物造模,药效评价 z-bio 2024-08-26 401

　　(1) Method of replication: Adult rats were fed a high-fat diet (supplemented with 1% cholesterol and 5% lard on the basis of a low-fat diet) after one week of normal feeding. At the same time, they were orally administered with 1.5ml/kg body weight of 60% ethanol twice a day for 12 consecutive weeks. At the end of the experiment, they were fasted for 16 hours. Blood was taken to prepare serum, liver tissue was taken to prepare homogenate, and paraffin sections were made for biochemical analysis and histological examination, respectively. Alternatively, while feeding a high-fat diet, 60% ethanol 15ml/kg body weight can be administered orally twice a day for 3-6 months. Or, at the same time of routine feeding, take the mixture of Baijiu, olive oil and pyrazole every day. The intake of Baijiu is 8~12g/kg body weight, and increases with time, that is, 8g in the first week, 10g in the second week, 12g from the third week, and then continue to maintain this amount until the end of the experiment. The intake of pyrazole is 27.2mg/kg body weight every day, once a day, for four consecutive weeks. Samples were taken 24 hours after the last infusion, and were embedded in conventional paraffin and electron microscope for histological observation.

　　(2) Model characteristics: High fat diet with 60% ethanol at a dose of 1.5ml/kg body weight was administered orally for 12 weeks. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholinesterase (ChE), triglycerides (TG), malondialdehyde (MDA), and liver tissue MDA in the model rats increased, while serum glutathione peroxidase (GSH Px), liver tissue superoxide dismutase (SOD), and glutathione (GSH) decreased; Under the microscope, liver cells can be seen to be significantly swollen, with loose cytoplasm and balloon like changes. There are also lipid droplets and vacuoles of varying sizes and quantities in the cytoplasm, as well as Mallory bodies and focal necrosis. Inflammatory cells infiltrate the interstitium. After a high-fat diet and oral administration of 15ml/kg body weight of 60% ethanol for 3 months, the model animals showed mild to moderate steatosis, an increase in the number of fat storage cells and a-smooth actin (a-SMA) positive cells in liver tissue. At 6 months, hepatic steatosis worsened, a-SMA positive cells increased, and fibrosis was observed around the central vein and sinus. Routine diet plus Baijiu, olive oil and pyrazole were administered by gavage for 4 weeks. Microscopically, the central area of the liver lobule of the model animal showed obvious necrosis, or focal necrosis, or dotted necrosis, and a large number of inflammatory cells infiltrated into the interstitial; Electron microscopy showed that the nuclei of the liver cells were irregular, with dilated and uneven perinuclear spaces; Cytoplasmic looseness, decreased electron density, and decreased number of organelles; Mitochondria swelling, deformation, disappearance of cristae, and a higher number of abnormal mitochondria; The rough endoplasmic reticulum expands, breaks, and exhibits degranulation, often presenting as large or small vesicles; Within the cytoplasm, lipid droplets and vacuoles of varying sizes and quantities can be seen, as well as filamentous arrangement of alcohol vesicles; Fat storage cells are functionally active, and their unique lipid droplet vacuoles decrease or disappear; Hypertrophic collagen fibers can be seen in the perisinusoidal space and around liver cells.

　　(3) Comparative medical alcoholic liver disease includes alcoholic fatty liver, alcoholic hepatitis, alcoholic liver fibrosis, and alcoholic cirrhosis, which are often progressive and partially overlapping. Since ethanol is absorbed in the gastrointestinal tract, the vast majority (over 90%) is metabolized in the liver through oxidation by ethanol dehydrogenase (ADH) and some microsomal enzymes (microsomal ethanol oxidation system). The main metabolite of ethanol is acetaldehyde, which has toxic effects on the liver and other organs. In clinical practice, different biochemical indicators can comprehensively reflect the degree of liver cell damage (ALT, AST), reserve capacity (ChE), and metabolic function (TBIL, TP, ALB, TG) from different perspectives, while histological examination is to some extent the most direct evidence for distinguishing alcoholic liver disease and its different stages of lesions. Mallory bodies are caused by the deposition of some cytoplasmic fibrin in swollen liver cells, which contain little or no fat and are a specific lesion of alcoholic liver disease. In addition, in the central zone of the hepatic acini, connective tissue around the hepatic sinusoids and hepatocytes can be seen, and collagen fibers form a continuous membrane like structure under the endothelium of the hepatic sinusoids. During the intermediate process of fatty liver developing into cirrhosis, diffuse inflammatory cell infiltration and necrosis can be observed in alcoholic hepatitis. Inflammatory cell infiltration and fatty liver are its characteristic lesions. The biochemical indicators and liver tissue morphology examination of the above animal models are basically consistent with the characteristics of human alcoholic liver disease, and are currently the main modeling methods used in China. Among them, the 12 week model of high-fat diet plus 60% ethanol 1.5 ml/kg body weight gavage is similar to the fatty liver disease of alcoholic liver disease, while the 6-month model of high-fat diet plus 60% ethanol 15 ml/kg body weight gavage or the 4-week model of conventional diet plus Baijiu, olive oil, pyrazole gavage is more similar to the pathological changes of alcoholic liver fibrosis. However, for the ethanol gavage replication model of alcoholic liver fibrosis, the former has a low formation rate and atypical lesions.