ABSTRACT
Objective To study Ephedra sinica in preventing hyperacute rejection in guinea pig-to-rat cardiac xenotransplantation. Methods The recipient rats were divided into two groups: control group and experiment group, according to whether administrated complement inhibiting component (CIC) from Ephedra sinica. In 15 min after operation, 4 rats from control group and 4 from experiment group were sacrificed to detect the pathologic changes in cardiac tissues. The complement parameters including CH_(50), APH_(50), and C_(3) were determined during the period of 0, 10, 15, 30, 45 min in serial serum. Results The survival time was significantly prolonged and pathological changes were less in experiment group than that in control group. Conclusion The study reveals that both classical pathway and alternative pathway of complement activation can be induced by xenotransplantation and Ephedra sinica can prolong the xenograft time by inhibiting complement activities and postposing hyperacute rejection.
ABSTRACT
The shortage of human hearts has brought the current research focus on finding an animal source as substitute hearts.The immunological barriers to cardiac xenotransplantation are now more clearly defined,allowing retrospective interpretation of past clinical experience in humans.Due to physiological compatibilities as well as ethical and infectious considerations,pigs have now emerged as the most likely source of future xenografts.With the introduction of transgenic pigs expressing human complement regulatory proteins and new immunosuppressive strategies have shown early promise in the laboratory,cardiac xenotransplantation has been the social focus.This article explores ethical issues that surround developments in this field.