Dynamic pathological changes in concordant cardiac xenograft rejection / 第三军医大学学报

ABSTRACT

Objective To explore the mechanism of delayed xenograft rejection(DXR) by dynamic observation of histological and immunohistologic changes in mouse-to-rat cardiac xenografts.Methods A model of mouse-to-rat cardiac heterotopic xenotransplantation in neck was established by cuff technique.NIH mouse hearts not transplanted served as controls(n=4).Some xenograft recipients were killed and cardiac xenografts harvested at end of 3,8,16,24 h(n=4 for each time point) after transplantation.The cardiac hearts(n=16) of some xenograft recipients were not harvested until rejection time to determine their survival time.All heart samples were examined by HE and immunohistochemistry for semi-quantitative determination of antibodies including C3,IgM,IgG,E-selectin and macrophage marker——CD68.Results During the period after transplantation,the degree of rejection of xenografts became more and more serious till ultimate rejection.The mean survival time of the xenografts was(49.3?16.2) h.Immunohistochemical examination showed C3 were not detected in the xenografts at any time during the course of rejection;From 3 h after transplantation,obvious deposition of IgM was found in the grafts and IgG deposition got abundant;E-selectin expression was found as early as 3 h after transplantation and increased gradually;There was progressive infiltration by macrophages in the grafts.Conclusion Mouse-to-rat cardiac xenotransplantation can serve as an animal model of DXR.Endothelial cells activation,IgM and IgG,macrophage infiltration involve in DXR development except C3.