动物造模,药效评价,急性胃溃疡 z-bio 2024-08-26 504

　　(1) Method of replication: Adult experimental mice were fasted and kept in water for 48 hours. They were orally administered anhydrous ethanol (5ml/kg body weight dose), acetylsalicylic acid (200mg/kg body weight dose), or 0.6mol/L hydrochloric acid (10ml/kg body weight dose). After 1 hour, the animals were euthanized by cervical dislocation method, and immediately laparotomy was performed. The pylorus and cardia were ligated, and a 1% formaldehyde solution was injected into the stomach. The stomach was fixed in the same concentration of formaldehyde solution, and after 30 minutes, it was cut open along a large bend, turned outward, and the contents were poured out. The gastric residue was gently rinsed with water to observe the degree of mucosal ulcer damage in the glandular stomach, and evaluated using the ulcer index. If the ulcer length is greater than 1mm, measure its length, and score 1 point for every 1mm. If the width is greater than 1mm, double the score. If it is a small ulcer point, score 0.5 points. Adding up the scores gives the ulcer index of the animal. Adult rats were fasted without drinking water for 48 hours, and were orally administered with 5ml/kg body weight anhydrous ethanol or intraperitoneally injected with 20mg/kg body weight indomethacin. The former was euthanized 1 hour after administration, while the latter was euthanized 4 hours after administration. 10ml of 10% formaldehyde solution was drawn using a syringe and injected into the stomach through the esophagus, and the needle was removed and ligated. Cut off the esophagus and duodenum at both ends of the online ligation, and remove the entire stomach. After 30 minutes, cut open along the major bend and examine the bleeding points and focal mucosal defects in the glandular stomach. The size and quantity of bleeding and ulcer lesions are used as indicators to measure the length and diameter of each ulcer, and the sum is used as the ulcer index. At the same time, histological observation of gastric mucosal lesions can be performed using light and electron microscopy techniques.

　　(2) After administering anhydrous ethanol, acetylsalicylic acid, and hydrochloric acid to mice, the gastric mucosa of the model mice showed significant damage, mainly manifested as a significant increase in ulcer index. Similarly, administering anhydrous ethanol to rats resulted in an increase in the total length of glandular gastric ulcers and the appearance of linear bleeding; Intraperitoneal injection of indomethacin significantly increased the number of gastric ulcer injuries in rats.

　　(3) Comparative medicine: Acute gastric ulcer is a disease that occurs in the body due to various factors such as sudden and severe damage to visceral function, alcohol abuse, and excessive use of certain steroid preparations. Under physiological conditions, the surface of the gastric mucosa is covered with a protective layer mainly composed of mucus and bicarbonate secreted by the surface epithelium, forming a surface microenvironment that can reduce or avoid direct contact between gastric acid and pepsin and the mucosa. In this environment, a healthy mucosa can clear H+reflux from the gastric cavity through blood circulation, synthesize prostaglandins that are beneficial for mucosal blood circulation, and maintain vigorous cell metabolism and regeneration function on the mucosal surface. When excessive amounts of strong acid, ethanol, or non steroidal preparations (such as acetylsalicylic acid, indomethacin, prednisone, etc.) are injected into the stomach in a single or short period of time, these exogenous substances can disrupt the microenvironment and induce acute gastric ulcers. The mouse model of acute gastric ulcer induced by chemical substances usually uses ulcer index as an indicator to determine the occurrence and degree of ulcers. On this basis, the rat model can also use indicators such as histological changes for assessment. This model has clear triggering factors, simple operation methods, low cost, and good experimental reproducibility, and has become one of the most commonly used experimental models.