动物造模,十二指肠溃疡动物模型 z-bio 2021-11-03 500

　　(1) Feeding method: Adult rats are fasted for 24 hours without watering for 2 hours, anesthetized to open the abdomen, expose the duodenum, and place a glass tube or latex tube with an inner diameter of 3 to 6 mm near the rat local. Start... the duodenum. Inject 70μl of glacial acetic acid into the tube from the other end of the front wall slurry surface (about 0.5 cm from the pylorus), remove the glass tube after 30 seconds, and quickly absorb the remaining glacial acetic acid with a filter. paper. The omentum was sewn on the surface of the glacial acetic acid application site, and the abdominal wall was sutured. 72 hours after the operation, the laparotomy was anesthetized again, the duodenum and attached peritoneum were taken out together, the duodenum was cut longitudinally from the other side where glacial acetic acid was applied, and the duodenum was treated with normal saline. Clean and observe the duodenum, observe the damage of the intestinal mucosa under a dissecting microscope, measure the ulcer area with a grid micrometer, fix the tissue, HE stain, and observe histological morphology.

　　(2) The characteristic of the model is that 72 hours after the operation, the animal's duodenal smear adhered to the omentum, and an ulcer similar in shape and size to the cross-section of the glass tube appeared on the mucosal surface. The ulcer has a clear boundary, with a crater-like ridge on the edge, covering an area of 22-36 square millimeters. Under the microscope, we can see that the ulcer wall is very steep. The bottom of the ulcer passes through all layers of the duodenal wall and reaches the omentum. Necrotic tissue is deposited on the bottom of the ulcer. Twenty-three days after the operation, the surface of the ulcer became smaller, shallower, and irregular in shape. It can be seen under the microscope that the connective tissue at the bottom of the ulcer is hyperplastic, covered with a single layer of columnar epithelium, and the connective tissue at the end of the ulcer has several intestinal crypts.

　　(3) Comparative medicine The mechanism of action of an animal model of duodenal ulcer caused by acetic acid is to directly destroy the barrier function of the duodenal mucosa by using the corrosive effect of acetic acid. Therefore, controlling the concentration of acetic acid, the area used and the contact time with the duodenum are important contents of the model method. When conducting experiments, you can usually find the best combination through pre-tests. Compared with the animal model of gastric ulcer caused by acetic acid, this method only needs to reduce the concentration of acetic acid and the contact time with the duodenum. The advantage of this model is that it has a clear susceptibility, easy operation and low price. The disadvantage is that the extent of the disease is difficult to control, and improper control can easily lead to ulcer perforation. In addition, the location of ulcers in this model is different from that of humans. The former ulcers occur on the serosal surface and the latter on the mucosal surface.