The Experimental Study Of High Expression With HO-1 To Induce Immune Rejection After Cardiac Xenotransplantation Of Guinea Pig-to-rat

Objective This study was designed to investigate the effect of the high expression with HO-1 on the immunological rejection of cardiac xenograft,which through the model of guinea pig to rat abdominal cardiac xenotransplantation.The mechanisms of rejection in xenotransplantation will be explored in the model.Materials and methods In order to increase the expression of HO-1,the donors and the recipients were injected with heme through abdomen before operation.The donors(guniea pig) and the recipients(SD rat) were divided randomly into seven groups.Group A(Control group):The heart from guinea pig was transplanted into the abdomen of SD rat;Group B(CVF group):the recipients were injected with chinese cobra venom factor(CVF) 40u/kg in abdomen and 24 hours later CVF 60u/kg were injected in vein again just before transplantation;Group C(CVF+ Paraffin-embedded group):24 hours before transplantation,the recipients were injected into abdomen with 15 ml fluid wax,and the fluid wax was drew out before transplantation.,CVF was injected as group B;Group D (CVF+ HO-1 high expression group):two days before transplantation the donors and the recipients were injected with heme 75μmol / kg through abdomen,and 24 hours later heme was injecter at the same way,CVF was injected as group B.The grafted heart mean survival time(MST),the mixed cell reaction(MCR),the expression of CCR5,ICAM-1 and the pathology in recipients were observed.The grafted heart mean survival time(MST),the pathology in recipients,the positive area of HO-1 in the heart of the donors,the expression of CCR5,ICAM-1 and the NK activity in recipients were observed.Results 1.MST(min):Group A(27.17±4.07min),Group B:(41.00±1.095min), Group C:(56.17±2.137min),Group D:(83.67±4.719min),The MST of Group C＞Group B(p＜0.05),The MST of Group D＞Group B(p＜0.05),The MST of Group C and D were prolonged significantly.2.Pathology:The donor heart in group A showed hyperacute rejection(HAR) change.Delayed xenograft rejection(DXR) change were taken place on other groups.3 the HO-1 positive area in the donors'hearts the results in group D is much higher significantly than group A,group B and group C(P＜0.05).4.the results of ICAM-1 and CCR5 in the peripheral blood of recipient's(pg/ml):the results in group D is much lower significantly than group A,group B and group C(p＜0.05).5.the NK activity in the peripheral blood of recipient's(%):the results in group D is much lower significantly than group A,group B and group C(P＜0.05).Conclusion 1.The MST can be prolonged by increasing the expression of HO-1 or embedding the macrophage,but AVR could not be overcomed completely.2.The activation of vascular endothelial cells,can be reduced by increasing the expression of HO-1.3.The NK activity can be reduced by increasing the expression of HO-1.