动物造模,药效评价,糖尿病心肌病 z-bio 2024-09-23 323

　　1. Experimental animals: Wistar rats, weighing 120-150g, male or female not limited.

　　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 at the end of the fourth week. At the end of the 20th week (under intraperitoneal anesthesia with 1% pentobarbital sodium 20mg/kg), the maximum rate of left ventricular pressure drop (dp/dt) during isovolumic diastole was measured by carotid catheterization. Color Doppler detection of left ventricular ejection fraction (EF): After euthanizing the rats, the heart weight (HW) was measured.

　　4. Reference results: From the beginning of injection of streptozotocin (STZ), Wistar rats became emaciated, had dry fur, fatigue, drank and ate more, urinated more frequently, had cloudy urine, and had a higher number of deaths. Under light microscopy, the main manifestations are vacuolar degeneration of myocardial cells and focal dissolution of myocardial fibers, as well as interstitial fibrosis of 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 and MDA and NO content.