疾病动物模型,白喉毒素,心肌炎模型 z-bio 2021-11-04 398

　　(1) Breeding method: For experimental mice weighing 25 to 30 g, first observe the experimental animals for 3 days, then select healthy animals and model them. The modeling method is to pass the diphtheria toxin stock solution through the tail of the mouse at a dose of 7.30. μ/g body weight. Intravenous injection. Thirty minutes after the injection, the drug should be injected after the diphtheria is basically absorbed. Observation indicators include (1) body temperature. The rectal temperature was measured 4 times every 24 hours 2 days before the experiment and before the administration of diphtheria toxin until death. ②Record breathing, general activity and food intake every 6 hours. ③ The electrocardiogram was started 2 days before the start of the experiment and was performed twice a day. Method: Insert needle electrodes into limbs and chest. (4) In cardiology, after the death of each mouse, the chest cavity is opened, the heart is taken out, and pathological specimens are prepared, which are sliced and observed with an optical microscope and an electron microscope. ⑤Monitor and record the time of death every hour.

　　(2) Model characteristics: The mouse myocarditis model caused by diphtheria toxin is an early-onset acute progressive disease, and the survival time of model animals is as short as about 2 days. 6 hours after the injection of diphtheria toxin, the body temperature of all animals increased, with an average of 0.9°C. Compared with the electrocardiogram before the experiment, after 24 hours, the PR interval of each group was prolonged, the ST segment was increased, the heart rhythm of all animals was accelerated, and the rhythm was irregular. The main pathological changes are myocardial cell degeneration and necrosis, sarcoplasmic degeneration and progressive myolysis, and inflammatory cell infiltration.

　　(3) Comparative medicine Clinical diphtheria patients often suffer from acute diphtheria toxic myocarditis. When mice were injected intravenously with diphtheria toxin, the acute myocarditis model caused by clinical diphtheria infection had many similarities in etiology, symptoms, signs and pathological changes. Symptoms include elevated body temperature, abnormal ECG, degeneration and necrosis of myocardial cells, accumulation of sarcoplasm, progressive myolysis, and inflammatory cell infiltration.