Rat model of diabetes mellitus and the changes of PPARγ and GLUT-4 expressions in adipose tissue

Objective:To develop rat model of diabetes mellitus and to explore the effects of peroxisome proliferator activated receptor γ（PPARγ） and glucose transporter 4（GLUT-4） in the diabetic rats induced by high fat diet and low dose streptozotocin（STZ） injection.Methods: Thirty-five Wistar male rats were divided randomly into normal control group（NC,n=15） and diabetic group（DM,n=20）,DM group rats were fed with high fat diet and injected with a low dose of STZ（30 mg/kg） once after 5 weeks.The rats with fasting blood glucose higher than 11.1 mmol/L detected one week later were chosen as the diabetic models（n=15）.The serum biochemical parameters were detected after 17weeks.The expression levels of PPARγ and GLUT-4 in adipose tissue were determined with immunohistochemistry and western-blot,respectively.Results: Compared with NC group,DM group got higher FBG,Hemoglobin A1c（HbA1c）,Triglyceride（TG）,glucosylated serum protein（GSP,P＜0.01）,elevated tumor necrosis factor alpha（TNF-α,P＜0.05） and lower insulin sensitivity index（ISI,P＜0.05）.Immunohistochemistry showed lower protein expression of PPARγ in adipose tissue of DM group compared with NC group（P＜0.01）.Western-blot analysis showed the expression of GLUT-4 in adipose tissue decreased significantly compared NC group（P＜0.01）.Conclution: Decreased protein expressions of PPARγ and GLUT-4 in adipose tissue may play important roles in insulin resistance,hyperlipemia and glucose homeostasis disorder in diabetes mellitus.