Objective Tri ptol ide can suppress immunological rejection reaction. To investigate the effect of tri ptol ide on allogenic tendon transplantation in repairing tendon defect in chicken. Methods The defect model of the third toes tendon was establ ished in 64 healthy-cleaning male Leghorn chickens (4-month-old, weighing 1.9-2.3 kg), which underwent allogenic tendon transplantation for repairing and were divided into 2 groups randomly (n=32). Tri ptol ide feeding[100 μg/(kg·d)] was given for 3 weeks in the experimental group and normal feeding in the control group. General condition of the chickens was observed after operation. The transplanted tendons were harvested from 4 chickens in each group for gross observation at 1, 2, 3, and 4 weeks after operation; the histological observation was performed at 1 and 3 weeks, and transmission electron microscope observation at 2 and 4 weeks. The blood and tendon were harvested from another 8 chickens in each group for flow cytometry and biomechanical tests respectively at 3 and 6 weeks. Results All chickens survived to the experiment end. Gross observation: with time extending, hyperemia and edema around transplanted tendon were rel ieved. Rarefaction adhering zone was seen in experimental group, and pyknotic adhering zone in control group. Histological observation: inflammatory reaction in experimental group was sl ighter than that in control group at 1 and 3 weeks. Transmission electron microscope observation: at 2 and 4 weeks, fibroblasts had big cell nucleus, more euchromatin, and l ittle heterochromatin in experimental group; however, there were small amount of rough endocytoplasmic reticulums with gentle expanded capsular space in control group, which contained sparse content. Flow cytometry test: at 3 and 6 weeks, peri pheral blood contained less CD4+ and CD8+ T lymphocytes in experimental group than in control group, and the ratio of CD4+ to CD8+ T lymphocyte significantly decreased in experimental group when compared with control group (P lt; 0.05). Biomechanical examination: at 3and 6 weeks, the maximum tensile strength in experimental group was bigger than that in control group, and tensile adhesion power in experimental group was smaller than that in control group. There were significant differences in the indexes between 2 groups (P lt; 0.05). Conclusion Tri ptol ide can suppress immunological rejection reaction, strengthen tendon healing strength, and reduce tendon adhesion in allogenic tendon transplantation.
Objective To investigate the anti-rejection effect and the mechanism of triptolide （TPT） on islet allo- grafts in a murine model. Methods BALB/c mice were used as islet donor. C57BL/6 mice were rendered diabetic by streptozotocin （STZ） injection， and transplanted with islets under the left kidney capsule. The recipients were randomly （method of random digits table） divided into three groups （n=8）. The mice in the treatment groups were injected intrap-eritoneally with TPT at 50 μg/kg （low-dose TPT group， L-TPT group） or 100 μg/kg （high-dose TPT group， H-TPT group） daily in the first 5 days and then on alternate days until 14 days；while the mice in control group were given vehicles （1% tween 80）. Blood glucose after operation were monitored. The grafts were defined as rejection when two consecutive reading of blood glucose＞20 mmol/L. The left kidney of three recipients in each group were resected for pathological examination. The proportion of CD4＋CD25＋Foxp3＋ regulatory T cells in spleen tissues were tested by flow cytometry. Results The median survival time of islet allografts from the control group， L-TPT group， and H-TPT group were 12.6 days （9-16 days）， 21.4 days （14-27 days） ， and 27.6 days （19-34 days）， respectivly. The percentageof CD4＋CD25＋Foxp3＋regulatory T cells in spleen tissues of three groups were （5.2±0.6）%， （12.0±1.3）%， and（15.7±1.8）%， respectivly. Compared with control group， the median survival time of islet transplantation in mice exte-nded and the proportion of CD4＋CD25＋Foxp3＋ regulatory T cells in spleen tissues increased （P＜0.05）. Conclusions TPT could increase the percentage of CD4＋CD25＋Foxp3＋ regulatory T cells， reduce the rejection after islet transplanta-tion， and prolong the survival time of islet transplantation in mice. The immunosuppressive effect of TPT shows a dose-dependent.