动物造模,应激性胃溃疡动物模型 z-bio 2022-02-06 770

　　(1) Reproduction method Adult rats, fasted for 24 hours, no water, anesthetized with ether, lying on the back, connect the animal’s limbs and neck to the rat plate, and cut about 2 cm of the lower abdomen along the middle of the abdominal wall and the abdomen .. Use metal to stretch and fix the screen frame, and then open the abdomen. After waking up, they were immersed in a constant temperature artificial sea bath at (21±2)°C to raise the water level to the same level as the Xifoid process. Sternum for 3 hours. After soaking, the animal was taken out, the skin was wiped dry, bleeding, and an autopsy was performed immediately. The location of the sample, testing and evaluation methods are the same as in the animal model of stress gastric ulcer caused by water immersion control.

　　(2) Model characteristics After seawater immersion, the gastric juice pH value of the animal model of laparotomy injury decreased, and the gastric mucosal ulcer index increased, and there was a negative correlation between the two. After 3 hours of seawater soaking pressure, a large number of knots ab adhered to the mucosal surface of the proventriculus, causing extensive erosion, bleeding and ulcers. Under the microscope, you can see that the normal mucosal layer of the injured area has been severely damaged. The surface of the necrotic epithelium is covered by a large number of red blood cells. The ulcer is like a volcanic crater, deep into the mucous membrane. Mucosal hyperemia and edema are obvious.

　　(3) Comparative medicine Seawater injury is a particularly strong source of pressure, with dual pressures of trauma and seawater immersion. After the peritoneum is exposed to hypertonic seawater, it will produce dialysis, which will gradually cause hypertonic dehydration, hypovolemic shock and metabolic acidosis, thereby increasing the level of free radicals, promoting tissue peroxidation, and leading to secondary organs. The injured gastric mucosa is extremely sensitive to ischemia and hypoxia. Under severe stress conditions, such as trauma and shock, the hemoperfusion of the stomach is initially affected and eventually returns to normal. Severe stress reactions often occur in acidosis, especially in shock, which can reduce the intracellular HCO3- content of gastric mucosa, reduce the ability of cells to neutralize H +, and cause acute gastric mucosal damage and stress ulcers. The model replicated by this experimental method has typical lesion features, clear evaluation indicators, and gastric acid secretion and mucosal damage are closely related to stress time. The longer the stress time, the lower the pH of the gastric juice and the more severe the mucosa. damage. The model has the characteristics of simple operation and high reproducibility. It is not only suitable for early pathophysiological studies of open wounds infiltrated by seawater, but also an ideal experimental animal for acute stress gastric ulcers, and it is also suitable for models. In the process of copying this model, attention should be paid to the influence of various factors on the model, such as the standardization of operation and the invariance of environmental conditions, especially the size of the animal, gender, degree of anesthesia, wound size, location, etc. .. Hemostatic quality, water temperature, pressure time. Under the premise of not affecting the operation, the anesthesia should be as shallow as possible; the bleeding should be accurately stopped during the operation to avoid chronic bleeding and aggravate shock; the abdominal incision should not be too large to fix the organ, and anesthesia should not be used. Protruding from the abdominal cavity. The abdominal incision should not be too high. Otherwise it will affect your breathing.