Effect Of Hypoglycemia On Oxidative Stress And Vascular Endothelium Cells And Oxidative Stress Of Diabetic Mice

Objective:To ascertain the influence of insulin-induced acute hypoglycemia on vascular endothelium cells(VEC) and oxidative stress of Diabetic Mice.Method:Healthy male Wistar mice were divided randomly into normal group and diabetic group,one week after adaptability,the normal group was fed with standard laboratory diet and the diabetic group was fed with high-fat diet for 8 weeks. Then the mice in diabetic group whose body wight were above 340g were chosen and injected intraperitoneally with streptozotocin (Sigma) at a dose of 25 mg/kg body weight. One week later, the glucose concentration was determined in tail blood samples, and only those with blood glucose above 16.7 mmol/L were considered as diabetic mice.Normal mice were divided randomly into control group(NC) and hypoglycemia group(NL),streptozotocin induced type 2 diabetic male Wistar mice were divided randomly into control group(DC),hypoglycemia group(DL),hypoglycemia followed by hyperglycemia group(DLH) and treating group(DT).After 12h fasted, hypoglycemia groups were injected with Biosynthesis of human insulin.1.5h after injection,the NLH group was given 50% glucose solution 3ml intragastric administration,other groups were given normal sodium 3ml intragastric administration.Blood samples were obtained from heart at the time before injection and 1.5h,4.5h,6.5h after injection.DT group was treated with Biosynthesis of human insulin Protamine 3u,4u subcutaneous injection at 6am and 6pm for 2 weeks. Blood samples were obtained from heart before and after treatment.After detected by glucometer, the blood serum was separated and used to detected MDA,SOD and ET-1.Result:â‘ Blood glucose:The blood glucose of insuline-injection groups reached the minimum at 1.5h after injection,and then the NL,DL groups'blood glucose increased slightly,DLH group'blood glucose increased significantly.The blood glucose of DT group lowered down 2 days after treatment and kept stable for 2 weeks.â‘¡MDA:The MDA level of NL group reached the maximum 4.5h after injection,then decreased.DL,DLH groups' MDA level decreased and reached the minimum at the time 4.5h after injection,then increased. DT group'MDA level lowered down after treatment.â‘¢ET-1:The ET-1 level of NL group reached the maximum at 1.5h after injection,and then decreased.DL and the ET-1 level of DLH groups' elevation was more obvious at the time 6.5h after injection,and the DLH group' ET-1 level increased more higher than the DL group'.DT group'ET-1 level lowered down after treatment.â‘£SOD:The activity of SOD in each group didn't changed significantly.Conclusion:(1)VEC injuiry and oxidative stress exist in type 2 diabetic mice,insulin treatment can reduce the VEC injuiry and oxidative stress of Type 2 diabetic mice.(2)Hypoglycemia can lead VEC injuiry,and the diabetic endothelium cells can be injuried more easily by hypoglycemia than health groups.(3)Glucose fluctuation induces endothelial dysfunction more obviously than uncontrolled hypoglycemia and hyperglycemia.(4)Sever hypoglycemia can lead to oxidative stress.