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,P0.01),elevated tumor necrosis factor alpha(TNF-α,P0.05) and lower insulin sensitivity index(ISI,P0.05).Immunohistochemistry showed lower protein expression of PPARγ in adipose tissue of DM group compared with NC group(P0.01).Western-blot analysis showed the expression of GLUT-4 in adipose tissue decreased significantly compared NC group(P0.01).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.