动物造模 z-bo 2022-02-03 370

　　[Modeling mechanism] Large doses of adrenaline directly stimulate β receptors, increase cardiac autonomy, conductivity, hypersensitivity, etc., and cause arrhythmia (ventricular premature beats, ventricular tachycardia, and even ventricular fibrillation). Even movement). Such as chloroform and adrenaline aggravate the toxicity to the heart.

　　Rat: Choose a 6-8 week old rat weighing about 200 g, anesthetize it and fix it on the back, cut the skin in the groin, and separate the femoral vein. 5. Pierce and fix with a scalp needle, and then connect the constant-speed infusion pump. The rate of intravenous adrenaline is constant. Insert the needle electrode into the rat's limbs subcutaneously, connect to the electrocardiograph and electrocardiograph, and record the normal Lead II electrocardiogram after the operation. Inject 1 ml of 0.9% sodium chloride intravenously, and record the ECG at 0, 1, 2, 3, 4, and 5 minutes to exclude animals with arrhythmia. Eligible rats were selected to inject 40 μg/kg of epinephrine intravenously at a constant rate of 1 ml/min. Record the administration time and closely observe the animal's ECG changes on the oscilloscope. After the injection, record the ECG for 30 seconds and then every 10 seconds until the ECG is completely normal.

　　Rabbit: Choose a rabbit weighing about 2.5 kg, fix it on the back with the rabbit fixing plate, fix the head with the rabbit head clip, pierce the needle electrode under the skin of the limbs, and connect the electrocardiogram to the machine and ECG oscilloscope. Cover the mouth and nose of the rabbit with an anesthesia mask. Slowly drip chloroform onto the anesthesia mask for anesthesia, and pay attention to the corneal reflex. After the corneal reflex disappeared (approximately when the first stage of the third stage anesthesia entered), the normal lead II ECG was immediately recorded, and then 0.5 ml/kg body weight of 0.01% epinephrine solution was immediately administered from the ear border vein. injection. Record the electrocardiogram, then every 30 seconds until the heart rhythm returns to normal.

　　[Model Features] Quickly introduce the model. Epinephrine, paroxysmal tachycardia, and even ventricular fibrillation quickly show one or more causes of premature ventricular contractions. It usually lasts about 4-7 minutes, and most animals can fully recover sinus rhythm within 10 minutes. .. Since the animals in this model will not die and can be tested at fixed intervals of one day, the self-control method can be applied to the same animals to reduce experimental errors due to individual differences.

　　[Model Evaluation and Application] The model method is simple, the response is fast, the maintenance time is short, and it can be repeated any number of times. You can control the degree of arrhythmia by increasing or decreasing the dose of adrenaline. It is only controllable, and it is not easy to produce rapid resistance. It is suitable for researching drugs for the prevention and treatment of ventricular tachycardia. In anti-arrhythmic drug screening research, it is advantageous to use small animals as a model to perform large-scale screening tasks. The method is simple and does not require special equipment, and the incidence of chloroform-induced ventricular fibrillation is high and easy to observe. However, this method can cause various types of arrhythmia, and they develop each other. This will not lead to comparison of effects between drugs. Therefore, during the application of the model, the following points should be noted: ① When using chloroform anesthesia, the amount of chloroform has a greater impact on the experimental results, so the depth of anesthesia should be as consistent as possible. It must be (2) Because the arrhythmia continues, the injection rate of adrenaline must be high. The time is short, requiring timely observation, accurate calculation and recording.