动物造模,慢性胃溃疡动物模型 z-bio 2021-10-14 262

　　(1) Regeneration method BALB/c mice, SPF grade, 5-7 weeks old, fasting for 12 hours, anesthetized and laparotomy, placed a second surgical cotton thread containing corrosive drugs on the posterior wall of the large curve of the stomach (Put 15 Cover the entire stomach wall with 20% carbon dioxide and 25% acetic acid solution, separate the two needle points 1-1.5 meters, cut off the cotton thread, close the abdomen according to the operation requirements, sew the skin, and restore normal water and food after the operation On the second hour, the next day, fasting for 12 hours, intraperitoneal injection of 0.25 mg of Lanitidine, 4 hours, through microbiology and PCR identification, forced oral administration of 14×100000000 CFU of Hp strain. Dislocation kills the spine and collects the gastrointestinal tract Tract mucosa, homogenate, observe the growth of bacterial clones, perform urea and PCR identification, participate in gastric mucosal tissue, optical inspection, and use electron microscopy or Mongolian gerbils (Mongoliangerbil, MG), 8 weeks old, fasting for 12 hours, Orally take 0.3 ml/head of 50% ethanol, and then continue fasting. On the next day, give 0.5 ml of 1000000000000 CFU/LHp bacterial solution to the stomach once in the morning and afternoon, or inject SPF grade 6-week-old MG again in the morning. Eat for 24 hours, subcutaneously inject indomethacin 20 mg/kg body weight; 6 hours later, give 0.5 ml of Hp bacterial solution by gavage, and continue fasting for 4 hours, so take gavage once a day for 3 consecutive days; 12 weeks later, Fasting for 24 hours, eye bleeding, serum separation, anti-Hp antibody. ELISA test, open the stomach at the same time, open the stomach along the lordosis to observe the gastric mucosa with naked eyes, culture half of the mucosal tissue, smear, rapid urea paper test, the other half Fix with 10% formaldehyde for histopathological examination.

　　(2) Model characteristics: Model mice have cotton thread containing corrosive drugs suspended under the mucosa of the gastric antrum for 2 weeks, and ulcers appear in the gastric antrum with a diameter of 1 to 2.5 mm. The mucosal gland defect, fibrous exudate and inflammatory cell infiltration can be seen under the mucosa. At the same time, the gastric mucosa was cultured in Hp conditioned medium for 3 days, and milky white colonies were visible. On the 72nd day of bacterial urease, the gastric mucosa had laparotomy under electron microscope observation. Helicobacter pylori. It was revealed. After 12 and 24 weeks of ethanol and Hp infection, about 37% of the model MG gastric mucosa had obvious bleeding, chronic active gastritis and ulcers. While the ulcer reaches the muscle layer, it may reach the antrum and focal spots. A large amount of Hp can be clearly seen between the surface mucus of mucosal epithelial cells, gastric glands and epithelial cells, and the Hp infection rate reaches 100%. After 12 weeks of indomethacin and Hp infection, a large number of inflammatory cell infiltrations were found in the mucosa of the gastric tissue of the MG model, and a large number of lymphoid follicles were formed in the mucosa and submucosa, and gastric ulcers were seen.

　　(3) Comparative medical studies have shown that Hp infection is closely related to the formation and development of gastric ulcers. Hp has a certain affinity for gastric epithelium, quickly penetrates the mucosal layer and penetrates the tight junctions between epithelial cells, causing inflammatory cells to infiltrate the mucosa, destroying surface epithelial cells and mucosa, resulting in decreased resistance and extracellular proteases. The rupture of the polymerized structure of mucus glycoprotein released by Hp can prevent mucus from forming colloids and destroy the integrity of the mucosal barrier; Hp secretes a large amount of urea and the surrounding environment of epithelial cells will rapidly decompose urea to produce a large amount of urea ammonia. As the pH value increases, H + enters the gastric cavity from the fundus glands, and the back diffusion of H + promotes the formation of gastric ulcers. In addition, Hp may also produce chemotactic inflammatory cytokines, such as lipopolysaccharide. This makes the chronic inflammatory mucosa more susceptible to damage by gastric acid. Although the proportion of people naturally infected by Hp is very high, it is difficult to colonize Hp by oral administration to small laboratory animals. This is not only because the quality of Hp colonization is related to the specificity of the animal host. The grade of the animal is not only related to the aggressiveness of the horsepower strain. In contrast, the small animals that are easy to colonize are gerbils. Animal grade is sterile grade or SPF grade. The Hp strain is a highly invasive strain. The latter refers to the high toxicity obtained through clinical isolation and animal screening and breeding. Strong power and strong adhesion. During the replication of this model, ranitidine has been pre-injected intraperitoneally. The purpose is to increase the pH value of the animal's gastric mucosa (the average value is changed from 1 to 5) to increase the number of Hp bacteria that enter the gastric cavity. It cannot be degraded after oral administration. Urea is used to establish a strong acid-resistant microenvironment to survive, so as to improve the ability of Hp bacteria to colonize the gastric mucosa. Pretreatment of experimental gabil with a certain amount of ethanol may damage the gastric mucosal tissue, destroy the gastric environment, cause ecological damage to the gastric flora, and promote Hp colonization. The use of indomethacin will increase the sensitivity of the gastric mucosa to Hp after Hp vaccination. Indomethacin and Hp infection cause gastric mucosal damage through different mechanisms, but jointly destroy several important methods, causing gastric mucosal cells to pass. Increase transparency. , And the fragile gastric mucosa is directly exposed to gastric acid and pepsin, which greatly increases the risk of gastric ulcer. The two have synergistic and cumulative effects.