Study Of Immunological Rejection And Calcification In Transplantation Of Aortic And Pulmonary Homograft

Objective: SD rats were used as experimental animal in the set-up of cryopreservation method of aortic and polmonary homograft. Animal model of homograft transplantation was established to investigate the effect of cryopreservation on the antigenticity of the aortic homografts, to observe the immunological rejection and calcification of the aortic and pulmonary homografts after implantation,and to study the effect of immunosuppressive treatment on aortic homograft transplantation.Methods: In this study,liquid nitrogen cryopreservation method was adopted in the long-term storage of the aortic and pulmonary homografts. The scanning and transmitting electron microscope and trypan blue staining were used to observe the effects of cryopreservation on endothelial structure and viability of aortic and pulmonary homograft. The animal models of aortic and pulmonary homograft transplantation were established by heterotopic insertion of aortic and pulmonary homografts into the abdominal aortae of SD rats. The combination of CsA and splenectomy was employed in treatment of immunological rejection in the immunosuppressive treatment group of aortic homograft transplantation.Respectively at 3th,7th,14th,21th,28th and 56th day after implantation,the blood samples of the transplanted animals were collected, and the homografts retrieved. Immunohistochemical staining was performed to detect the IgM and IgG deposition, MHC class I and class II antigen expression of the aortic and pulmonary homografts. The biological activities of IL-2 and TNF-α in blood samples of the transplanted rats were measured by means of indicator cell culturing method. The effect of cryopreservation on expression of MHC class I antigen of the smoth muscle cells and fibroblasts of aortic homografts was determined by flow cytometric method. Macro electronic probe technique was employed in determination of the calcium content of the explanted aortic and pulmonary homografts. Results: The cryopreservation may maintain more than 90 percent viability and normal intercellular connections of the endothelial cells of the aortic and pulmonary homografts. The IgM and...