Establishment Of Allograft Heterotopic Heart Transplantation Model In Rats And The Anti-immune Rejection Of Halofuginone

Halofuginone(HF),also known as halofuginone,is a kind of alkaloid constituent extracted from Chinese herb antifebrile dichroa which has extensive beneficial biological activities.Keller's research found that HF not only has the efficacy of anticoccidiosis,can also regulate immune system function.Studies have shown that HF can effectively prolong the survival time of graft and improve the survival rate of the recipients.However,the effects of HF on CD4~+CD25~+Foxp3~+ regulatory T cells in the process of immunological rejection remain unclear.Since the medicinal value of HF has been documented by research,this article will discuss about the mechanism of the effects of HF on anti-rejection through the result of heterotopic heart transplantation.This study will provide some theoretical basis for the method for solving immunological rejection in organ transplantation.The animal model of allogeneic heterotopic heart transplantation was established by taking Wistar rat as donor and SD rat as receptor.The experimenter summarized the experience of successfully building this model.In this study,we analyzed the effects of HF on CD4~+CD25~+Foxp3~+ regulatory T cells in Allogeneic rats with heterotopic heart transplantation through the impact of HF on animal model.All 24 Wistar rats and 24 SD rats were divided into two groups(with 12 Wistar rats and 12 SD rats in each group).The group B(Administration)were orally administered with HF in three days before and four days after the heterotopic heart transplantation while the group A(control)received oral administration with physiological saline as control.The rats were observed and evaluated every day after operation,the B-ultrasound,ECG and palpation were used to observe the survival time of the graft and the beating condition.The grafts were taken on the third,fifth and seventh postoperative day for HE staining to observe myocardial injury and inflammatory cell infiltration.On the fifth day and the seventh day after the operation,the peripheral blood,lymph node and spleen were collected and detected by flow cytometry to test the expression of CD4~+CD25~+n Treg.5 days and 7 days after operation,Real-time Quantitative PCR was performed on the spleen from two groups of animals to detect the expression of Foxp3~+.Postoperative observation and evaluation of resultsGroup A(Control): On day 0,the mental status of group A was good and the intake of food and water was normal.The cardiac impulse was strong,heart rate about200 beats/ min.On the third postoperative day,the receptor response was reduced and the amount of food consumed as well as activities of the subjects was decreased.The donor heart began to darken and the heart beat diminished.On the fifth postoperative day,receptor response was the same as the third day and the experimental objects react slower.The donor heart became dull-red and dark.Group B(Administration): On day 0,the mental status of group A was good and the intake of food and water was normal.The cardiac impulse was strong,heart rate about 200 beats/ min.On day 3 and day 5 receptor response was the same as day 0.The donor heart appeared bright red with no obvious thrombosis and necrosis.The results of HE staining:The observed result of pathology section for the heart on the third,the fifth and the seventh day after the operation as follows: Group A(Control)showed increasingly severe myocardial injury and a large number of inflammatory cell infiltration in the low power lens.Myocardial cell swelling and severe vacuolar degeneration were observed under high power microscopic view.Group B(Administration)'s myocardial lesions were slighter than that in the control group.The inflammatory cells infiltration and edema were observed in the myocardium under the low power lens.The vacuolar degeneration,edema and inflammatory cells were less than the control group.The results of flow cytometry:On the fifth day and the seventh day after the operation,the peripheral blood,lymph node and spleen were collected and detected by flow cytometry in two groups.The results showed that the CD4~+CD25~+Foxp3~+ regulatory T cells in the experimental group were markedly increased in spleen and lymph nodes while significantly decreased in peripheral blood.The results of Real-time Quantitative PCR:5 days and 7 days after operation,Real-time Quantitative PCR was performed on the spleen from two groups of animals.The results showed that the level of the expression of Foxp3 gene in the experimental group was remarkably higher than that in the control group.Conclusion: the model of heterotopic heart transplantation in rats was successfully established,and the effect of halofuginone on immunological rejection in heterotopic heart transplantation model in rats was studied.