动物造模 z-bo 2022-10-11 587

　　[Modeling mechanism] After the pylorus is ligated, the gastric juice remains in the stomach, and the action of gastric acid and pepsin is enhanced. The stomach expands the antrum due to the pylorus ligation, and the reflex stimulates the secretion of gastrin, leading to excessive gastric acid secretion.

　　[Modeling method] Wistar rats, male and female, 150-225g. After fasting for 12 hours (free drinking water), oral aspirin (200 mg/kg), fasting for 18 hours and intraperitoneal injection of ketamine hydrochloride (50 mg/kg) and ligation of the pylorus. The animals were sacrificed 4 hours after the operation, the stomach was opened, the esophagus was clamped and the stomach was taken out, the gastric juice was carefully collected and the amount of gastric juice was recorded. The total acidity, pepsin activity and mucin content of gastric juice were measured. The lipid peroxide, endogenous superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) in gastric tissue homogenate were measured. The stomach was immersed in 1% formaldehyde for 10 minutes, and the stomach was incised along the larger curvature of the stomach. The number of ulcers was observed and the ulcer index and ulcer incidence were calculated. The results showed that the incidence of ulcers in the aspirin and pyloric ligation groups was 100%. In severe cases, the ulcers would reach the muscle layer or even perforate. Compared with the control group or ranitidine group, the ulcer index or grade was significantly increased, the total acidity of gastric juice and pepsin activity were significantly increased, and the amount of mucin was significantly reduced. Lipid peroxide levels increased significantly, while the levels of SOD, CAT and GSH decreased significantly.

　　[Model Features] The pyloric ligation model is more in line with the "self-digesting" theory of human peptic ulcer, but when the pylorus is ligated, the mucosa is mainly caused by acute bleeding and erosion. When aspirin is present (as mentioned above, aspirin itself) has a milder effect, mainly local erosion, this combination will produce typical pathological symptoms of human peptic ulcer. The lipid peroxide level in the gastric tissue of the model group increased significantly, but the levels of SOD, CAT and GSH decreased significantly. This indicates that the antioxidant activity of gastric mucosal cells and tissues is reduced, damage is increased, and repair functions are weakened. [Model Evaluation and Application] Pyloric ligation is a traditional and classic method to establish a rat model of gastric ulcer, with a high success rate, a reliable method, and high repeatability. However, pyloric ligation alone has the least effect on the formation of ulcers, and when combined with other stimuli, it becomes a typical disease.