动物造模,肝硬化模型 z-bio 2021-03-24 404

　　(1) Regeneration method Adult rats were anesthetized by umbilical cord median sternotomy, and the common hepatic bile duct was sutured 1 cm away from the hilum with 7-0 silk thread. It should be stored for 2-8 weeks after surgery. During this period, observe the general activity and physical signs of the animal, and dynamically draw blood from the orbit to alanine aminotransferase (ALT), total bilirubin (TBIL), alkaline phosphatase (ALP), hyaluronic acid And prepare the serum. (HA) Content detection. After the modeling is completed, the liver is taken out and weighed. After cutting, a part of the tissue is harvested to prepare a homogenate with hydroxyproline (Hyp), total protein (TP), malondialdehyde (MDA) and superoxide dismutase content. For (SOD) measurement, a part of the tissue was fixed with 10% formaldehyde solution, embedded in conventional paraffin, the section was stained with HE or Masson, and a part of the tissue was stained with 1% 4% glutaraldehyde. It is fixed with tetroxide and coated with conventional paint. The 618 epoxy resin was embedded, the sections were made with an ultra-thin microtome, and were stained with uranium-lead, and the tissue morphology was examined using an optical microscope and electron microscope.

　　(2) After 5 weeks of model feature modeling, the wet weight of liver and spleen and the coefficient of model animals increased significantly, serum ALT, TBIL, ALP, liver tissue Hyp, MDA, and liver tissue TP increased. , SOD is reduced. Optical microscopy showed degeneration, necrosis, and inflammatory cell infiltration. The liver tissue of the model animal gradually spread out 1-2 days after the operation and became very obvious on the third day. At the same time as the above changes, small bile duct-like epithelial cells appear around the portal vein lobules, and gradually expand, elongate and deepen over time, and the lobules become flower-shaped. On the 35th day, the small bile ducts and related fibroblasts, collagen fibers and capillaries formed a membranous space that connects adjacent hyperplastic spaces, surrounds and separates them, until pseudolobules are formed. Under the electron microscope, 1-2 days after the operation, atrophy and degeneration of single or 2-3 liver cells were scattered around the lobules, the nucleus was purulent, the cytoplasm was dense, and the organelles were degeneration. See necrosis and inflammatory cell infiltration, phagocytosis accumulation. At the same time as hepatocyte degeneration and necrosis, small bile duct-like epithelial cells appeared and proliferated around the lobules, with basement membrane and collagen fiber layer on the basal side of the vesicle structure. After one or two weeks, small bile duct-like epithelial cells proliferate and gradually form, extending along the hepatocyte line from around the lobule to the inside of the lobule. After 3 weeks, bile duct-like epithelial cells clearly differentiated and evolved, and most of them appeared to differentiate into bile ducts. Epithelial cells become cubic or flat, cytoplasmic intermediate filaments increase, and nuclear envelope sinks to form irregular shapes. Chromatin gathers under the nuclear membrane, the lumen is enlarged, and the microvilli are sparsely distributed. The proliferation of collagen fibers around the small bile ducts gradually forms a transparent layer of collagen fibers. The proliferating small bile ducts and their associated phagocytic cells, mast cells, inflammatory cells, fibroblasts, capillaries, and proliferating collagen fibers together form a partition between liver cells. Some small bile duct-like epithelial cells differentiated and evolved into hepatocytes, and transitional epithelial cells and hepatocytes in the form of vesicles were seen. It is usually wrapped in a transparent layer of collagen fibers to form small liver cell nodules. Typical collagen fibrous hyperplasia and hepatocyte nodules were observed within 8-12 weeks.

　　(3) Comparative medicine Extrahepatic bile duct obstruction causes bile duct dilatation, cholestasis, and increases pressure in the bile duct above the obstructed site, causing intrahepatic bile duct dilation and rupture, hepatocyte ischemia and necrosis, and ultimately can lead to hepatocyte ischemia And necrosis. Bile liver fibrosis and cirrhosis. Common bile duct ligation completely blocked the bile ducts of the model animals, accumulated in the gallbladder, accumulated in the gallbladder, induced the production of free radicals in the liver, and caused lipid peroxidation of the cell membrane (increased MDA, decreased SOD) and increased permeability. And the resulting imbalance of cell metabolism in cell structure and membrane damage. Lipid peroxidation causes a chain reaction, which further aggravates liver cell damage and necrosis (decreased TP). The massive ischemia and necrosis of hepatocytes induce the appearance of small bile duct-like epithelial cells. The latter proliferate through a kind of pluripotent stem cell, and may have proliferation and differentiation functions. In the case of hepatic necrotizing liver damage, small bile duct-like epithelial cells differentiate into follicular or nodular hepatocytes, and synthetic collagen participates in the proliferation of collagen fibers (increased Hyp) in liver cirrhosis, accelerating the formation and attack. This model can better simulate the process and consequences of human liver fibrosis and cirrhosis caused by long-term cholestasis. The modeling method is simple, the cycle is moderate, the reproducibility is good, the success rate is high, and the price is expensive. At present, in addition to rats, rabbits, dogs, monkeys and other animals with biliary cirrhosis induced by common bile duct ligation have also been successfully and widely used at home and abroad.