动物造模,药效评价,心肌病模型 z-bio 2024-07-02 394

　　1. Experimental animal: Wistar rats, 120-150g, regardless of gender.

　　2. Experimental methods: The rats were fed with a high sugar and high fat diet (10% lard, 20% sucrose, 2% cholesterol, 1% sodium cholate, 67% conventional diet) for 4 weeks, and venous blood was collected for fasting (fasting for 10 to 12 hours, during which free drinking water) blood glucose (glucose oxidase method) and insulin level determination. After insulin resistance was caused, they were given intraperitoneal injection of streptozotocin (STZ) [15mg/(kg · W) × 4] every week from the fifth week, with fasting blood glucose ≥ 16.7mmol/L (on the basis of insulin resistance, fasting blood glucose<16.7mmol/L, excluding the diagnosis of diabetes), and continued to eat a high sugar and high fat diet for 20 weeks.

　　3. Experimental observation content: Fasting blood glucose, insulin, and insulin resistance index over the fourth weekend. At the end of the 20th week (intraperitoneal injection anesthesia with 1% pentobarbital sodium 20mg/kg), the maximum rate of left ventricular diastolic pressure decrease (dp/dt) was measured through carotid artery catheterization. Color Doppler detection of left ventricular ejection fraction (EF): After euthanizing the rats, the heart weight (HW) was measured.

　　4. Reference results: After the initial injection of streptozotocin (STZ), Wistar rats showed emaciation, dry fur, fatigue, excessive drinking and eating, frequent urination, cloudy urine, and high mortality rates. Under light microscopy, the main manifestations are vacuolar degeneration of myocardial cells and focal dissolution of myocardial fibers, as well as proliferation of interstitial fibers in the myocardium; Under electron microscopy, the main manifestations are myocardial mitochondrial dilation, shortening of cristae, dissolution of myofibrils, proliferation of interstitial collagen fibers, decreased SOD activity, increased NOS activity, MDA, and NO content.