动物造模,药效评价,肝纤维化 z-bio 2024-08-26 407

　　(1) Methods Adult rats were fed Baijiu (ψ (C2H5OH)=0.56) 7g/kg body weight by gavage once a day in the morning for 24 weeks. Or give Baijiu corn oil pyrazole mixture by gavage once a day in the morning for 12 weeks. The proportion of intake of each component in the mixture is: daily Baijiu [ψ (C2H5OH)=0.56] 8~12/kg body weight, corn oil 2g/kg body weight, pyrazole 24mg/kg body weight, and intermittent high-fat diet. Among them, ethanol intake gradually increases with time

　　Step by step. The following formula is used for the calculation of ethanol dosage: ethanol dosage (g)=volume of Baijiu (ml) × volume fraction of Baijiu (0.56) × relative density of ethanol (0.8g/ml). During the modeling process, the general condition and weight changes of the animals were observed daily. After modeling, whole blood was extracted to prepare serum for serum biochemical testing, and the liver was taken to measure its wet weight, which was converted into organ coefficients and subjected to histological examination.

　　(2) The characteristics of the model were simple Baijiu. At the 4th week of modeling, the animals appeared salivation, stiff posture, lethargy, mental depression, anorexia, and movement retardation. The contents of serum aspartate aminotransferase (AST) and alkaline phosphatase (ALP) increased, and the contents of total protein (TP) and globulin (GP) decreased. Bridging necrosis occurred in the central and portal areas of adjacent hepatic lobules in some rats' liver tissues. A large number of inflammatory cells infiltrated in the necrotic areas, mainly neutrophils, showing moderate to severe inflammatory changes; At 12 weeks, the animal's hair luster decreased, weight growth slowed down, and there was frequent diarrhea. The liver volume increased, the color became dull, and the texture became harder. Most animal liver tissues showed varying degrees of watery and balloon like degeneration, with liver cells under the liver capsule being the most obvious, and hepatic cell lipid degeneration worsened with an increase in lipid droplets; At 24 weeks, animal serum AST remained at a high level, ALP recovered from high levels to normal range, and albumin (ALB) content significantly decreased. Blood stasis was observed in the small arteries and veins of the hepatic portal area, as well as in the central veins and sinusoids of the liver lobules. Transparent thrombus appeared in the central veins, some central veins dilated, basement membrane thickened, endothelial cells of blood vessels and sinuses swollen, collagen fibers deposited along the sinus wall in a wire mesh or turtle shell like pattern, with a wide range. Collagen fibers could also be seen in and around the portal area. In severe cases, collagen fibers thickened in the central veins and portal area, and fibrous septa appeared in the lobules, but the lobular structure was normal and the boundary plate was intact. Baijiu corn oil pyrazole mixture was administered by gavage. After drinking, the model animal was in a drunken state of limp limbs and deep sleep, with loose fur, low spirit, loose stool sometimes, diet gradually reduced, and weight decreased in the later period. After 12 weeks of modeling, the liver of the model animal became dark, the edge became blunt, the surface was uneven, and some of the white spots were raised. The degeneration and necrosis of liver cells were obvious, showing fatty degeneration, watery degeneration, and ballooning degeneration. Local neutrophils and a few lymphocytes infiltrated. The periphery of the terminal hepatic vein, the portal area, and the portal area showed mild to moderate fibrosis, of which the perisinus fibrosis was obvious, and the sinus wall reticular fibers were seen in mild cases. It is thickened and straightened, inserted between hepatocytes, or even wrapped around one or several hepatocytes, but the lobule structure remains, In moderate cases, collagen fibers can be seen depositing along the sinus perimeter, surrounding liver cells in a grid like or turtle shell like pattern, with a wide range of coverage.

　　(3) There is a close relationship between medical ethanol and the occurrence of liver fibrosis. After ethanol is absorbed in the gastrointestinal tract, it is oxidized by the body's enzyme system to produce acetaldehyde, which is the main metabolite of ethanol and can continue to be oxidized to acetate. Acetaldehyde has toxic effects on the liver and other organs. During the conversion of ethanol to acetaldehyde and acetaldehyde to acetate or acetyl CoA (NAD), reduced nicotinamide adenine dinucleotide (NADH) can also be produced. The decrease in the ratio of NAB/NADH inhibits the hepatic tricarboxylic acid cycle, weakens gluconeogenesis, and increases fatty acid synthesis. When its increase exceeds the liver's processing capacity, fatty liver is formed, ultimately leading to liver fibrosis. Based on the etiology and pathogenesis of alcoholic liver disease in humans, a rat model was established by continuously administering ethanol into the stomach for 24 weeks while feeding solid feed. This model allows for observation of changes in animal general behavior, serum biochemical indicators, and tissue morphology at different stages. The main feature of this model is that it can observe and evaluate the pathological changes in various stages of chronic alcoholic liver disease induced by single factor ethanol, except for alcoholic cirrhosis, through biochemical and morphological indicators, which is more in line with human clinical practice. However, its disadvantage is that the experimental period is too long. The gavage model of Baijiu corn oil pyrazole mixture is based on ethanol gavage. By adding high-fat raw materials that can promote or aggravate alcoholic liver injury, corn oil rich in unsaturated fatty acids and pyrazole, an alcohol dehydrogenase inhibitor, which is easy to induce fatty liver inflammation and liver fibrosis, are quantitatively mixed in ethanol to promote the formation process of liver fibrosis. The biggest feature of this model is its high rate of liver fibrosis modeling, stable model, relatively short modeling cycle, easy operation, and low cost. It has been widely used in China.