Effects Of Oxidative Stress And Expression Of PDX-1 Of Pancreanic Islet In Type 2 Diabetic Rat

OBJECTIVE: To study the effects of oxidative stress on pancreanic islet function and the protection of antioxidants in type 2 diabetic rats. METHODS: The Wistar rats were injected intraperitoneally with low-dose(20mg/kg) of STZ after high fat diet for three months.The rats were divided into three groups: the control group were fed conventional diet, the diabetes group and the diabetes-probucol treatment group(the probucol group); Then the probucol group were treated with probucol(500mg/kg·d,) for one month.PBG and fasting serum FBG,TG,T-ch,FINS were measured in all groups.The levels of MDA,NO,SOD and GSH-PX in pancreatic homogenates were also detected. The expression of PDX-1 and insulin in pancreatic islets were determined by immunohistochemical assay. RESULTS: (1)In diabetic rats, the MDA, NO level in pancreatic homogenates were higher than those of control group, while the SOD,GSH-PX level and both PDX-1 and insulin expressions were lower(P <0.01). (2)After treated with probucol the MDA, NO level in pancreatic homogenates were lower than those of untreated diabetic rats, while the SOD,GSH-PX level and both PDX-1 and insulin expressions were higher(P <0.05). (3)PDX-1 expression in islets was negtively correlated with the level of MDA and NO, but correlated with the level of SOD,GSH-PX(P <0.05). CONCLUSION: Pancreatic function in type 2 diabetic rats are affected by oxidative stress resulting in decreasing expressions of PDX-1 and insulin in pancreatic islets.Antioxidant can preserve pancreatic islet-function against damage from oxidative stress.