Biochemical and metabolic characteristics of the experimental rats with insulin resistance and diabetes

Objective To study biochemical and metabolic characteristics of the rats with insulin resistance and diabetes induced by high fat diet and low dose streptozotocin.Methods Twenty male Sprague-Dawley rats were divided into experimental group(high fat diet,n=10) and control group(normal diet,n=10) according to random digit table.After 4 weeks,streptozotocin(35 mg/kg) was intraperitoneally injected into the rats in experimental group.Rats with plasma glucose≥16.67 mmol/L were taken as successful diabetic model and continuously fed with high fat diet.The changes of body weight,plasma glucose,triacylglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C) and microalbuminuria(MAU) were measured at 1,4 and 8 weeks after modeling.Intraperitoneal glucose tolerance test(IPGTT) and intraperitoneal insulin tolerance test(ITT) were also performed 1 and 8 weeks after modeling.Results Compared with control group,the body weight of the rats in experimental group was significantly increased 1 week after injection of streptozotocin(P0.01),but significantly decreased 4 and 8 weeks after injection of streptozotocin(both P0.01).TG,TC,LDL-C,plasma glucose and MAU in the experimental group were significantly increased 1,4 and 8 weeks after injection of streptozotocin(all P0.01).IPGTT and ITT showed abnormal glucose tolerance and decreasing insulin sensitivity.Conclusion There are abnormal glycolipid metabolism and increasing insulin resistance in the diabetic rats induced by high fat diet and low dose streptozotocin,which is similar to the pathophysiolgical changes of type 2 diabetic patients in clinic and can be used in the experimental researches of type 2 diabetes and its chronic complications.