Expression And Significance Of P-selectin In Type 2 Diabetic Rats

Objective : Vascular disease is the main reason of deformity and death in diabetic patients. So, it is important to lucubrate the Vascular disease, confirm it's mechanisms, and develop effective treatment to delay the happening of Vascular disease. P-selectin belongs to adhesion molecules. It is a kind of antigen of platelet chorion. And part of them fall to the blood plasma. The expression of sP-selectin can reflect the degree of active platelet. The aim of this study is to observe the dynamic change of sP-selectin by duplicating the diabetic rats model ,which were measured the level of sP-selectin at 0 ,4 ,8 ,12 and 16 weeks after the success of the diabetic model ;At the same time spots ,the index of blood lipid and FBG were measured .The study want to analysis the relationship between sP-selectin and active platelet ,vasal embolism. Through which the mechanism of the complication of diabetes was understood and the evidence of therapy were offered early .Methods : 120 healthy 7 weeks old Wistar rats were included ,which weighed 180-220g ,and half were male and half were female(bought from the Experimental Animal Center of Hebei Medical University) . The rats were randomly divided into two groups : control group(CON) with 50 rats and trial(TIR) group with 70 rats .The rats of control group were fed on standard diet ,which included protein 23%,carbohydrate 50%,fat 5% ,while the rats of trial group were fed on a diet enriched in fat to induce insulin resistance ,which included protein 20%,carbohydrate 48%,fat 22% .After 2 months ,the rats of trial group were injected intraperitoneally with a low-dose streptozocin(30mg/kg) to induce hyperglycemia ,and at the same time ,the rats of control group were injected intraperitoneally with sodium citrate buffer .One week later ,the glucose tolerance was assayed to determine the set-up of diabetic model .Both of the two groups were fasted for 10-12 hours before the blood sample were obtained from the tail vein to measure the fast blood glucose(FBG) ,and then the high carbohydrate glucose solution at the concentration of 50% according to 2g/kg were perfused into the stomach of all the rats .2 hours later ,the same method was used to measure the 2 hours blood glucose(2hBG) . The rats whose FBG≥7.0 mmol/l and 2hBG≥11.1 mmol/l were successful to be the diabetic model ,from which 50 rats (half of each sex) were selected to the diabetes group(DIA) .50 rats of DIA were divided randomly into 5 groups :DIA0,DIA1,DIA2,DIA3 and DIA4 with 10 rats each group ;50 rats of CON were divided randomly into 5 groups :CON0,CON1,CON2,CON3 and CON4 with 10 rats each group .The rats of CON were fed on standard diet and the rats of DIA were fed on diet enriched fat .The rats were weighed and the fasting blood glucose was measured every two weeks, and the rats of DIA were excluded if their FBG<7.0mmol/l.SP-selectin and the index of blood lipiod were measured regularly at 0,1,2,3 and 4 months after the build of the animal model .After fasting for 10-12 minutes ,the rats to be measured were anaesthesiaed ,then the blood sample were taken from the vena cava inferior ,5-7ml of the blood samples waited for coagulation under room-temperature ,then centrifugated by 3000/minute for 10 minutes ,obtained the serum from the blood ,the serum samples were kept in -80℃refrigerator ,then waiting for the collecting to measure sPselectin by ELISA .SAS software pack were used for all the data to make statistical-analysis .Initially the homogeneity of variance among all the groups was analyzed .All the measurement data was denoted by mean±standard deviation and students t test was used to establish significance.We took P<0.05 as statistic significant level .Results :1 The weight of rats of CON before glucose tolerance increased gradually ,and FBG of which were normal .The weight of TRI before the success of diabetes increased faster than which of CON ,and FBG of which were mormal too .(Table 1)2 After the set-up of the diabetes model , FBG of the rats of CON were stable and normal . There were no significant differences and comparable among the different time spots, including sP-selectin ,FBG of the rats of DIA were stable ,and hadn't increased or decreased obviously (P>0.05) .The weight of the rats of CON increased gradually ,while the rats of DIA increased slowly even decreased .3 In DIA ,P-selectin have already increased between 0 and 4 weeks,but there were no significant changes . on the time spot of 8 ,12 and 16 weeks ,the level of the sP-selectin increased obviously ,there were significant changes among them (P<0.0001) .(Table 2)4 In DIA ,with the improvement of diabetes mellitus ,on the time spot of 0 ,4 ,8 ,12 ,16 weeks ,the level of LDL increase obviously , and HDL decrease .there were significant changes among them (P<0.01) .(Table 2)5 The level of sP-selectin was positively correlative with LDL (r=0.642) and negatively correlative with HDL.(r=-0.658),P <0.01.Conclusions: The result of study confirmed that the level of sP-selectin increased in the course of diabetes mellitus , And since the 8th week there were significant changes .At the same time,the level of LDL increased, HDL deceased . The reason maybe unnormal cruor factor or cruor things in diabetic pathologic reaction , and a plenty of platelets were active .sP-selectin were released .By sP-selectin , adhersion happened between active platelet ,vascular endothelial cells and leucocyte , and become a important factor to thrombus. Therefore, it was necessary to measure the level of sP-selectin, which is helpful to estimate the condition and prognosis of diabetic patients.