Study Of The Effect And Mechanism Of TGF-β1 In Prevention Of Acute Heart Allograft Rejection

Objective To improve technique of rat cervical heterotopic heart transplantation and study cardiac transplantation rejective reaction. Methods On the basis of Chen' s method , The donor heart aorta and the right common carotid artery of the recipient were anastomosed using the end-to- side suture technique. Results The total ischeamic time of the graft was shortened to 25 min, and the 7 day survival rate of the recipient was increased to 97%by using the new technique. Conclusions The development of cervical heart transplantation in rat was a new, simple and useful technique, so it should be to spreaded. Part TwoStudy of the effect and mechanism of TGF-β1 in prevention of acute heart allograftrejection in ratsExperiment 1 Effect of TGF-β1 in prevention of acute heart allograft rejection inrats Objective To study the effect of TGF-β1 in prevention of acute heart allograft rejection in ratsMethods Model of rats cervical heterotopic heart transplantation was set up . The groups consisted of control group, TGF-β1 group, CsA group and TGF-β1+CsA group.Grafts survival days and transplanted heart beating conditions were observed every day. Results In TGF-β1 group CsA group and TGF-β1+CsA group, grafts survived days increased significantly compared with control group,especial!y in TGF-β1 +CsA group (P<0.01).In TGF-β1 group , grafts survived days increased significantly compared with CsA group(P<0.05). In TGF-β1 +CsA group, grafts survived days increased significantly compared with TGF-β1 group( P <0 .05) and CsA group( P <0.01). Conclusion TGF-β1 is able to suppress cardiac allograft rejection .It can prolong the survival days of transplanted hearts .It can cooperate with CsA and reduce the dose of CsA. Experiment 2 Effect of TGF-β1 on apoptosis of myocardial cells in rats heart transplantation rejectionObjective To study the effect of TGF-β1 on apoptosis of myocardium in rats heart transplantation rejection. Methods Mode! of rats cervical heterotopic heart transplantation was set up . At 1st 3rd 5th and 7th day after transplantation , apoptosis index was evalulated by the percentage of mycardial cells with TUNEL positive staining and the protein level expression of Bcl-2 and Bax were measured by immunohistochemistry methods. Results The apoptotic myocardial cells were significantly increased at 3rd day and the peak was at 7th day after transplantation in transplant group.The protein level expression of Bax in TGF-β1 group was significantly lower than that in transplant group (P<0.01). Apoptosis indexes of mycardial cells in TGF-β1 group were found significantly lower than those of transplant group (P<0.01). Conclusion TGF-β1 is able to increase the ratio of Bcl-2/Bax and protect myocardial cells against apoptosis in rats heart transplantation rejection. Experiment 3 Effect of TGF-β1 on expression of IL-12 IL-15 IL-18 IL-4 and IL-10 in rats heart transplantation rejectionObjective To study the effect of TGF-β1 on expression of IL-12 IL-15 IL-18, IL-4 and IL-10 in rats heart transplantation rejection. Methods Model of rats cervical heterotopic heart transplantation was set up . The groups consisted of control group, transplant group and TGF-β1 group. The mRNA level expression of 1L-12, IL-15, 1L-18, IL-4 and IL-10 were measured by RT-PCR at 5th day after transplantation. Results The mRNA level expression of IL-12 IL-15 IL-18 were significantly increased and IL-4, IL-10 were significantly decreased in transplant group(p<0.01). In TGF-β1 group,the mRNA level expression of IL-12, IL-15 IL-18 were significantly decreased and IL-4 IL-10 were significantly increased (p<0.01). Conclusion TGF-β1 is able to decrease the expression of IL-12 IL-15 IL-18 and increase the expression of IL-4 and IL-10 in rats heart transplantation rejection, and prolong the survival days of transplanted hearts. Experiment 4 Effect of TGF-β1 on expression of CD44 selectin-E LFA-1 VCAM-1 in rats heart transplantation rejectionObjective To study the effect of TGF-β1 on expression of CD44 selectin-E LFA-1 VCAM-1 in rats heart transplantation rejection. Methods Model of rats cervical heterotopic heart transplantation was set up . The groups consisted of control group, transplant group and TGF-β1 group. The mRNA level expression of CD44, selectin-E LFA-1 VCAM-1 were measured by RT-PCR at 5th day after transplantation. Results The mRNA level expression of CD44, selectin-E, LFA-1 VCAM-1 were significantly increased in transplant grour(p<0.01). In TGF-β1 group,the mRNA level expression of CD44, selectin-E LFA-1 VCAM-1 were significantly decreased (p<0.01). Conclusion TGF-β1 is able to decrease the expression of CD44, selectin-E LFA-1 VCAM-1 in rats heart transplantation rejection, and prolong the survival days of transplanted hearts. Experiment 5 Effect of TGF-β1 on expression of perform and granzyme B in rats heart transplantation rejectionObjective To study the effect of TGF-β1 on expression of peiforin and granzyme B in rats heart transplantation rejection. Methods Model of rats cervical heterotopic heart transplantation was set up . The groups consisted of control group, transplant group and TGF-β1 group. The mRNA level expression of perforin and granzyme B were measured by RT-PCR at 5th day after transplantation. Results The mRNA level expression of perforin and granzyme B were significantly increased in transplant group(p<0.01). In TGF-β1 group,the mRNA level expression of perforin and granzyme B were significantly decreased (p<0.01). Conclusion TGF-β1 is able to decrease the expression of perforin and granzyme B in rats heart transplantation rejection, and prolong the survival days of transplanted hearts. Experiment 6 Effect of TGF-β1 on expression of inducible nitric oxide synthase in rats heart transplantation rejectionObjective To study the effect of TGF-β1 on expression of inducible nitric oxide synthase(iNOS) in rats heart transplantation rejection. Methods Model of rats cervical heterotopic heart transplantation was set up . The groups consisted of control group, transplant group and TGF-β1 group. The mRNA level expression of iNOS was measured by RT-PCR at 5th day after transplantation. Results The mRNA level expression of iNOS was significantly increased in transplant group(p<0.01). In TGF-β1 group,the mRNA level expression of iNOS was significantly decreased (p<0.01). Conclusion TGF-β1 is able to decrease the expression of iNOS in rats heart transplantation rejection, and prolong the survival days of transplanted hearts.