动物造模,复张性肺水肿,药效评价 z-bio 2024-06-03 578

　　1. Animal modeling materials: Healthy rabbits weighing 2.5-3.5kg, both male and female; Medication: pentobarbital; Equipment: A 12F chest tube equipped with a valve (modified from a 12F catheter with a valve installed at the end of the urine bag) and a 60ml syringe.

　　2. Method of modeling: The animals in the modeling group were anesthetized by intravenous injection of pentobarbital (concentration of 30%, 1ml/kg) through the ear margin. A 12F chest tube with a valve was placed and fixed between the 3rd and 4th ribs on the right edge of the sternum. Gas leaked during tube placement was removed from the chest cavity, and 5ml of water was injected into the balloon to prevent slipping. The valve was bandaged and placed in the center of the back, fixed with adhesive tape. After anesthesia, slowly inflate 50-60ml (not more than 50ml for those weighing less than 2.8kg), and then inflate 8-15ml daily. The specific dosage is limited to the occurrence of obvious respiratory distress. After 7 days, pentobarbital was anesthetized via the auricular vein, and the trachea was cut open and intubated. The right carotid artery was separated and a heparinized tube was placed, connected to a physiological recorder, and blood samples were prepared. Immediately after the start of the experiment, use a 60ml syringe to connect to the valve and quickly aspirate, and use a simple respirator to gently inflate the lungs several times to promote lung recruitment. Chest CT examination was performed before and 1, 3, and 5 hours after aspiration, and the average arterial pressure (MAP), heart rate (HR), and respiration (R) were recorded immediately, 30 minutes, 1 hour, 3 hours, and 5 hours after aspiration in rabbits confirmed to have pulmonary edema by CT examination. Blood gas was also monitored. After 5 hours, the animals were euthanized by bleeding, and the chest cavity was dissected to observe the condition of the heart and lungs. The lungs were taken for observation of general changes, and small pieces of tissue near the hilum of the lungs were taken for pathological examination (light and electron microscopy observation). After weighing the remaining lungs, they were placed in a 56 ℃ incubator. After 24 hours, the dry lung weight was measured, and the pulmonary edema index, lung wet dry ratio, and lung water content were calculated. Control group: Without special treatment, pentobarbital was injected into the ear vein for anesthesia, and 5 hours later, blood was drawn and euthanized for testing.

　　3. The principle of modeling is that negative pressure aspiration leads to pulmonary edema in animals during lung recruitment.

　　4. Changes after modeling: MAP, HR, and R were significantly higher from 30 minutes after aspiration than before. After 1 hour, blood pressure, heart rate, and respiration basically returned to normal; There was no significant change in the partial pressure of carbon dioxide (PCO2) and pH before and after pumping; The pulmonary edema index, dry lung weight, lung wet dry ratio, and lung water content in the experimental group were higher than those in the control group.

　　Imaging changes: A 30 minute CT scan reveals an increase in lung density on the right side, with a significant difference in density compared to the corresponding area on the left side. The changes are more pronounced at 3-5 hours.

　　Pathological examination: the right lung is slightly heavier than the left lung, and the volume of the edematous lung is significantly increased. The cut surface is foam shaped, and the middle and lower lobe of the right lung is the most important. Light microscopy examination: There is significant edema in the lung interstitium and alveoli, with infiltration of neutrophils and monocytes. Electron microscopy examination: infiltration of neutrophils and monocytes in the alveolar cavity, swelling of mitochondria and endoplasmic reticulum in type II epithelial cells, perinuclear fissures, and significant emptying of lamellar bodies.