动物造模,链脲菌素糖尿病动物模型 z-bio 2021-12-21 527

　　[Procedure] Adult rats, mice, dogs, monkeys and guinea pigs are all susceptible animals for the streptozotocin diabetes model. Dissolve streptozotocin (STZ) in citrate buffer (pH 4.0-4.5). The intravenous dose is:

　　Dog 30-50 mg/kg body weight, 50 mg/kg body weight 100% of animals can cause diabetes; 50 mg/kg dog body weight can cause diabetes, killing more than half of the animals. Mouse 175-200 mg/kg body weight can cause diabetes.

　　Other dosing methods can be used. By fasting the rats for 12 hours and injecting 60 mg/kg of STZ intraperitoneally once or twice a day, a rat model of type 1 diabetes can be successfully created. The characteristics of hyperglycemia, weight loss, polydipsia, polyphagia and polyuria are consistent with clinical type 1 diabetes. After fasting for 12 hours, STZ was injected intraperitoneally at 60 mg/kg body weight, STZ was injected intraperitoneally only once, and a high-calorie diet was given for 12 weeks, and then an animal model of type 2 diabetes was created. A model. The method is characterized by being overweight, impaired glucose tolerance, increased blood lipids, increased serum insulin, and decreased combination of insulin receptor and insulin resistance, similar to the clinical features of patients with type 2 diabetes. [Result analysis] Streptozotocin (STZ) is an antibiotic. In 1963, Laquieten reported that in addition to its anti-tumor effects, it also promoted the development of diabetes. Therefore, in current experiments, streptozotocin is usually used instead of alloxan to induce diabetes. At present, it is possible to artificially synthesize streptozotocin to obtain the same biological activity as natural streptozotocin, thereby reducing the content of nicotinamide adenine dinucleotide (NAD) in B cells and causing cell destruction. After using streptozotocin, blood sugar levels showed three stages of changes, and it was a persistent diabetic state. Histopathology showed that within 1-2 hours after the administration of streptozotocin, the nucleus and cytoplasm of B cells in rats and rabbits were destroyed, and the B cells were completely destroyed within 24 hours. Streptozotocin can induce diabetes in many animals.

　　(attention)

　　(1) Streptozotocin is a broad-spectrum antibiotic isolated from Streptomyces. It is a colorless solid and easily soluble in water. The aqueous solution is very unstable at room temperature. It decomposes into gas. Within a few minutes, the aqueous solution should be stored at pH 4 and low temperature. (2) After the diabetic dose of streptozotocin is injected, blood glucose levels can be observed in three stages, similar to alloxan injections. However, unlike alloxan, early hyperglycemia after streptozotocin injection is delayed by about 45-60 minutes before it starts. This delay did not appear in fasted mice, but it was obvious in rats. The hypoglycemia caused by streptozotocin is more serious than alloxan, and the corresponding fatal seizures are more common. Prevention and treatment measures are the same as alloxan.

　　(3) The diabetic effects of streptozotocin: streptozotocin can also selectively damage pancreatic islet B cells, and its histological changes are similar to alloxan diabetes. Guinea pigs that are resistant to the diabetic effects of alloxan can also cause diabetes. Compared with alloxan-induced diabetes, streptozotocin-induced diabetic ketosis and serum-free fatty acids in rats were significantly reduced.