Correlation Study Between Oxidative Stress With GLUT4Expression And Translocation In Type2Diabetic Rat Skeletal Muscle Cells

OBJECTIVE Research the effects of oxidative stress on GLUT4expression andtranslocation in type2diabetic rat skeletal muscle cells to explore the oxidative stressmechanism in diabetic rat skeletal muscle. METHODS The model of type2diabetic in rat was established by a single injection of streptozotocin at leftintraperitoneal combined with high-fat-sugar diet.40healthy SD rats were divided intodiabetic group, high-fat group and control group randomly. High-fat group and controlgroup was treated by a single injection of citrate buffer solution in same dose of at leftintraperitoneal. High-fat group fed with high-fat-sugar diet and control group fed withnormal diet. Observed general situation of the rats, and detected body weight andblood glucose weekly. The rats were killed after3months fed, heart blood serum wasprepared by centrifugation. Detected the levels of insulin, glucose, total cholesterol,and triglyceride and the oxidative stress indicators: Malondialdehyde, glutathioneperoxidase, manganese superoxide dismutase, catalase in the serum. The pathologicalchanges of liver and skeletal muscle were detected by HE staining. Expression ofGLUT4in skeletal muscle was determined by immunohistochemical staining andwestern blotting. Expression of GLUT4mRNA in skeletal muscle was determined byRT-PCR. Isolated the proteins in skeletal muscle membrane and cytoplasmic andGLUT4translocation detected by western.blotting. RESULTS (1) Type2diabeticrat model modeling success rate of80%.(2) Control group drunk less and less urine,fur smooth and supple, gradual increase in weight, blood sugar normal. High-fat groupwith the fast gained weight, smoothly fur, slowly activity and slowly raised bloodsugar. Diabetic group with the symptoms of varying degrees of polydipsia, polyuria,polyphagia, weight gain rapidly, matte fur, lack of energy, blood sugar significantlyincreased.(3)Compared with control group, the biochemical indicators of High-fatgroup tended to increase, but not statistically significant, and were significantly higherin diabetic group(P＜0.01).(4)HE staining: The morphology of liver and skeletal muscle was integrity in control group. High-fat group had varying degrees of disease.The diseases of liver and skeletal muscle in diabetic group were same with clinicalcases of type2diabetes.(5) Compared with control group, oxidative stress increasedsignificantly in diabetic group.(6) Western blotting: Expression of GLUT4on skeletalmuscle in High-fat group tended to decrease, and was significantly lower in diabeticgroup than the control group(P＜0.01).(7)RT-PCR: Compared with control group,expression of GLUT4mRNA in skeletal muscle of High-fat group and diabetic groupwere decreased significantly(P＜0.05, P＜0.01).(8)Compared with control group,expression of GLUT4in skeletal muscle membrane of High-fat group and diabeticgroup were decreased significantly(P＜0.01). Expression of GLUT4in skeletal musclecytoplasmic of High-fat group and diabetic group tended to decreased, but notstatistically significant.(9) Immunohistochemical staining: Compared with controlgroup, expression of GLUT4in skeletal muscle of High-fat group and diabetic groupwere decreased significantly(P＜0.01). CONLUSIONS (1) The experimental type2diabetic rat model was replicated successfully, and insulin resistance in vivo wasproved.(2)Oxidative stress related to GLUT4was present in skeletal muscle of type2diabetic rats.(3) Oxidative stress was inhibited on the translocation of GLUT4proteinsignificantly more than the expression.