The Effect Of Ischemic Reperfusion Injury On Acute Rejection Of The Transplanted Hearts

Objective: The models of beating heart transplantation designed by ourselves (continuous perfusion of donor heart with oxygenated blood in the beating state) and arrested heart transplantation with modified Heron's technique (myocardial preservation by hypothermy potassium arrest) were established to investigate the effect of ischemic reperfusion injury (IRI) on acute rejection (AR) of the transplanted hearts.Method: All cases were randomly divided into 5 groups. Each group included 7 animals. The all animals of the isograft groups provided the acceptors were SD rats. Beating group (A1 group) and arrested group (A2 group) were established according to the model of homogeneous heterotopic beating heart transplantation and the model of improved Heron's technique for heart transplantation separately. Allogeneous groups took the Wistar rat as the donor, took the SD rat as the acceptor. Beating group (B1 group) and arrested group (B2 group) were established according to the model of homogeneous heterotopic beating heart transplantation and the model of improved Heron's technique for heart transplantation separately. The group (no transplant) for the blank control group (C group) was set up. Specimens were collected 7 days after operation. The levels of expressing MHC-2mRNA and B7-1/B7-2 mRNA in the transplanted hearts were detected by reverse-transcription PCR. The method of immunohistochemistrial stain was applied to observe the CD4+T cell to donnor heart's infiltration situation. SPSS 13.0 statistical software was applied for data analysis, P-value less than 0.05 were considered significant. Used the One-Way ANOVA and analysis of variance compared the data of two groups.Results: Seven days after transplanted, The expressing of MHC-2 mRNA and B7-2 mRNA in group A2, B1 and B2 was higher than that in group A1 or group C (P<0.05). There were significant differences between MHC-2 mRNA and B7-2 mRNA in groups A2, B1 or B2 (P<0.05 for all). About CD4+T cells infiltration situation: C, A1 and A2 groups were 2.0±0.82, 3.14±0.69 and 4.86±0.90; respectively. CD4+T cells infiltration situation in B1 and B2 groups was 18.86±0.69 and 43.57±2.07; respectively. CD4+T cells infiltration was low in C group and two isograft groups, however, the infiltration in A2 group was higher than that in control group (P<0.05). CD4+T cells infiltration in two allogeneous groups (B1 and B2) significantly was higher than that in the former three groups (A1, A2 and C, P<0.01).Conclusion: The ischemic reperfusion injury can stimulate the expressing of many major immune factors. The IRI stimulates acute rejection in transplanted heart. It is beneficial to reduce the intensity of acute rejection occurrence after transplantation, since beating heart transplant avoid IRI in a large degree.