动物造模,药效评价,心肌缺血 z-bio 2024-09-23 384

　　1. Modeling material animals: Experimental miniature pigs, both male and female, weighing (16 ± 3.0) kg; Medication: Pentobarbital; Equipment: RM-6008 8-channel physiological recorder.

　　2. Modeling method: After intraperitoneal injection of pentobarbital anesthesia, the patient is fixed supine on the operating table and tracheostomy is performed for assisted breathing. Cut open the center of the sternum to expose the heart, and make a hammock by cutting open the heart cuff; Measure the length of the left anterior descending (LAD) branch of the coronary artery, free the artery at the junction of the lower one-third, and prepare to ligate it with line 4. Separate the common carotid artery and insert a catheter to connect a pressure transducer filled with heparin saline to measure arterial blood pressure; Insert a catheter from the apex of the heart into the left ventricle and connect it to a pressure transducer to measure left ventricular pressure (LVP); LVP electrical signals are processed using a differentiator to record the rate of left ventricular pressure rise (dp/dt); Record lead II electrocardiogram using subcutaneous needle electrodes. All the above parameters are synchronously recorded on the RM-6008 8-channel physiological recorder. Record the basic values of the above measurement indicators. Then ligate the LAD.

　　3. The modeling principle is to establish an acute myocardial ischemia model by opening the chest and ligating the left anterior descending coronary artery.

　　4. Changes in hemodynamics after modeling: After LAD ligation, myocardial contractility decreased, manifested by a decrease in Vmax and maximum rate of increase in left ventricular pressure dp/dt max at 15 and 30 minutes after ligation, respectively, and continued until 120 minutes after ligation without returning to pre ligation levels. There were no significant changes in the peak left ventricular pressure (LVP max), left ventricular end diastolic pressure (LVEDP), and mean arterial pressure (MAP) during each time period compared to before ligation. Heart rate (HR) starts to increase 15 minutes after ligation, reaches its peak at 30 minutes, and gradually returns to pre ligation levels after 90 minutes.

　　Epicardial electrogram: ∑ ST significantly increased at various time points after ligation, especially at 30 minutes after ligation. During the initial stage of ligation, frequent ventricular premature contractions can also be observed.

　　Myocardial infarction range: NB-T staining showed that the infarct range was (12.2 ± 4.0)% 6 hours after ligating the lower one-third of the pig LAD.

　　5. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections, surgical trauma should be minimized, and aseptic operation should be strictly enforced.