Expression And Significance Of VWF In Type 2 Diabetic Rats

Objective :The incidence of 2 diabetes mellitus is increasing daily for the past few years . The main reason for the prognosis of diabetic patients is the occurrence and extent of chronicity complication,which is related to the disfunction of great vessels and micro-vessels. With the depth of the studies ,people paid more attention to the role of the damage of endothelial cell. The high expression of Von Willebrand factor (vWF) is known as the sign of the endothelial cell damaged. vWF is one of the glycoprotein,which is synthesized and secreted by endothelial cell and giant plates..As the carrier of blood coagulation factorⅧ, vWF can makeⅧhalf life extent,maintainⅧliveness,strengthen clotting mechanism of intrinsic coagulation.On the other hand,as the"bridge"of adhesion between platelet and the endothelial cell damaged,it can make platelet attach on the damaged endothelial cell, assemble with the endothelial cell,and this is the first step of thrombus start.The aim of this study is to observe the dynamic change of vWF by duplicating the diabetic rats model ,which were measured the level of vWF at 0 ,4 ,8 ,12 and 16 weeks after the success of the diabetic model .The study want to analysis the relationship between vWF and active platelet ,vasal embolism. Through which the mechanism of the thrombus 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.After fasting for 10-12 hours ,the rats to be measured were anaesthesiaed with hydral(10%),then the blood sample were taken from the vena cava inferior ,5-10ml of the blood samples waited in EDTA cuvette,then centrifugated by 3000/minute for 10 minutes,obtainned the serum from the blood ,the serum samples were kept in -80℃refrigerator ,then waiting for the collecting to measure vWF(by ELASA).And also through DCA2000+, the blood(10μl) from vena caudalis waited for HbA1c ,urine (1ml) were collected for microalbumin.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 DIA before the success of diabetes increased faster than which of CON ,and FBG of which were normal too .2 After the set-up of the diabetes model , the weight of the rats of CON increased ,FBG of the rats of CON were stable and normal, no significant differences among the different time spots, FBG of the rats of DIA were high stablely,and hadn't increased or decreased obviously(P>0.05).The weight of the rats of DIA increased,no significant differences to the rats of CON at same time spots . (Fig 1,Fig 2)3 VWF of the rats of CON were no significant differences among the different time spots;In DIA,vWF has already increased at 0 weeks,but no significant changes ,from the time spot of 4 weeks ,the level of the vWF increased obviously to the rats of CON at same time spots (P<0.05) , vWF increased with the course of disease,and from the time spot of 8 weeks ,the level of the vWF increased obviously to the rats at former time spot(P<0.05). (Fig 3,Table 4)4 The level of HbA1c was positively correlative with vWF (r=0.712) (P<0.01) (Fig 4) and the level of vWF was positively correlative with microalbumin(r=0.896)(P<0.01). (Fig 5)Conclusions:1,The result of study confirmed that the level of vWF increased in the course of diabetes mellitus.2,The level of vWF increased was related to the increased HbA1c and microalbumin.3,Through the earlier monitor to vWF, the mechanism of the thrombus complication of diabetes was understood and the evidence of therapy were offered early .