动物造模,肺水肿 z-bo 2022-02-02 374

　　1. The purpose of the experiment

　　1. Understand the basic principles and methods of rat pulmonary edema model replication.

　　2. Further proficient in the basic experimental operations of rats.

　　2. Experimental equipment

　　1. One surgical scissors, one ophthalmic scissors, one medium and one ophthalmic flat tweezers, one balance, and three 2ml syringes.

　　2.0.1% adrenaline solution (1:1000), 6% ammonium chloride solution, 1 bottle of epinephrine for injection.

　　3. 3 rats.

　　Three, copy method

　　1. Weigh the rat

　　Put the rat into a carton of known weight and weigh it. After deducting the weight of the box, record the actual weight of the rat.

　　2. Administration

　　According to the body weight of the rats, 3 rats were administered respectively. The first rat was intravenously injected with 0.1ml adrenaline (0.1ml of 0.1% adrenal solution) per 100g body weight; the second rat was intraperitoneally injected with 6% chlorine per 100g body weight. 0.6ml of ammonium and 5mg epinephrine were injected intramuscularly in the third mouth.

　　3. Observed

　　Observe the changes of the animals after the administration. After the administration of the drug, the animals may have difficulty breathing. First, the animal may have a tachycardia, then raise the head to breathe, and then the respiratory rate will slow down and the heartbeat will stop. Most animals can see a pink foamy liquid from the nose. Finally, the whole body convulsed and died of heart failure. Generally live for tens of minutes. The above symptoms can be manifested differently due to different administrations, but they can obviously cause pulmonary edema.

　　4. Result judgment

　　After the death of the animal, take out the intact lungs (the trachea and blood vessels can be ligated with sutures) and weigh, calculate the lung weight and weight ratio, pulmonary edema index = lung weight × 1000 / body weight. It is generally believed that pulmonary edema occurs when the index is greater than 50. Observe the indications of pulmonary edema:

　　(1) The appearance is swollen, there is congestion in the middle, and the inflated alveoli are only visible at the edges.

　　(2) The weight increases, the lungs do not shrink, and the lungs are resilient.

　　(3) Water flows out of the cut surface, the center is concave, and the edge is slightly raised.

　　Fourth, the brief mechanism of replication

　　Toxic doses of epinephrine and iron amide can cause tachycardia, the left ventricle cannot fully discharge the injected blood, and the left ventricular pressure gradually increases at the end of diastole, which can cause the right atrium to increase the pressure and cause pulmonary vein congestion. The pulmonary capillary venous pressure also increases. Once it exceeds the plasma colloidal osmotic pressure, the formation of tissue fluid increases, and when the lymphatic flow cannot be fully returned, pulmonary edema can occur. Foamy liquid flowed out of the animal’s mouth before death, and foamy liquid was also filled in the respiratory tract after death, indicating that plasma enters the respiratory tract through the pulmonary blood vessels. Experiments have proved that during the formation of pulmonary edema, there is indeed a marker protein that enters the alveoli and bronchioles through blood vessels and alveolar membranes. Because plasma is rich in protein, bubbles are easily formed when gas flows through during breathing and are not easy to eliminate. Foam is formed very quickly, and a small amount of plasma can form a lot of foam, which will quickly fill the respiratory tract with foam, which will seriously affect gas exchange and cause animal death. But if the foam can be cleared in time, the volume of the liquid can be greatly reduced, thereby reducing the obstruction of the respiratory tract and quickly improving hypoxia. Together with other measures, it can often save lives and even fully restore lung function.