动物造模,药效评价,心肌病变 z-bio 2024-09-23 290

　　1. Six adult hybrid dogs with a weight of (17.04 ± 2.03) kg were used as experimental animals.

　　2. Experimental method: Sodium pentobarbital is prepared at a concentration of 3% and injected intraperitoneally at a dose of 1mg/kg. After anesthesia, perform echocardiography to measure the left ventricular diameter, left ventricular posterior wall, and interventricular septum thickness. Properly replenish fluids during the experiment. Prepare a dog model of third degree atrioventricular block using the Hirschsprung procedure for ablation. Then, a small incision was made on the right neck of the dog to expose the external jugular vein. After successful puncture using the Sedinger method, the guide wire, vascular sheath, and permanent pacing electrode were sequentially inserted. The fixed end of the electrode head is fixed at the apex of the right ventricle of the dog, and the electrode outlet end is sutured and fixed subcutaneously. The pacemaker is set to VOO mode, with a fixed frequency of 250 beats per minute, an output voltage of 5.0V, and a pulse width of 0.5 milliseconds. The electrocardiogram confirmed good pacing, sutured all incisions, removed the sheath of the right femoral vein to stop bleeding, and intravenously injected 20mg of furosemide for diuresis before anesthesia recovery. After the surgery, all dog models were raised for 3 weeks, and ultrasound examinations were repeated to measure relevant parameters for self comparison before and after. Then the dogs were euthanized, and their hearts were weighed as the model group. The maximum left ventricular diameter and maximum ventricular wall thickness were measured, and the specimens were stained with pathological sections (HE). Another group of 8 normal adult hybrid dogs were used as the control group.

　　3. Reference Results Experimental results: The model group had higher body weight, total heart weight, maximum left ventricular diameter, and maximum ventricular wall thickness than the control group. Cardiac ultrasound examination: comparison before and after the model: left ventricular chamber enlargement, left ventricular posterior wall and interventricular septum thinning. Pathological section: The myocardial cells in the model group were swollen with varying sizes, with vacuoles appearing in the cytoplasm and an enlarged perinuclear space.