Role and function change of vascular endothelial cells in chronic graft vasculopathy

Objective To study the role and function change of the vascular endothelial cells in chronic graft disease,and to study the protective effects of thalidomide on the development of allograft vasculopathy and its potential mechanisms.Method Rat abdominal aorta transplantation was performed on male Brown-Norway (BN) rats as donors and male Lewis rats as recipients.The recipients were divided into 3 group: allograft control group (BN-Lewis) and isograft control group (BN-BN) with administration of sodium chloride,and experimental group (BN-Lewis) administered with thalidomide for 60 days postoperatively.All recipients were killed to harvest transplanted aorta at 60th day after transplantation.HE staining was used to observe the histological changes.The vascular endothelial cell growth factor (VEGF) expression was detected by using immunohistochemical method.Electron microscope was used to observe the ultra-structure of the vascular endothelial cells and the smooth muscles.Result Isograft control group showed no obvious changes in transplanted aorta at 60th day after transplantation,but experimental group and allograft control group showed changes in pathologic morphology and ultra-structure related to the transplant vasculopathy to varying degrees.The pathological changes in experimental group were more severe than those in allograft control group.There was statistically significant difference between allograft control group and experimental group in the ratio of media and intimal thickness,and the number of cells positive for VEGF.Conclusion Thalidomide has protective effects on chronic allograft vasculopathy,which might be associated with the down-regulation of VEGF and the function change of the vascular endothelial cells. Key words: Vascular endothelial growth factors;  Graft rejection, chronic ;  Endothelial cell;  Rats