雷公藤内酯醇对致敏大鼠淋巴细胞凋亡的影响

目的 探讨雷公藤内酯醇（TP）体内外对致敏大鼠淋巴细胞淋巴细胞凋亡的影响。方法 采用卵蛋白（OVA）致敏并反复刺激建立过敏性气道炎症模型，24只SD大鼠随机分为正常组、阳性对照组和TP处理组，每组8只。用TUNEL原位末端标记法，DNA电泳及电镜等方法，观察体内外TP对致敏大鼠淋巴细胞凋亡的影响及机制。结果 致敏大鼠BALF中嗜酸性粒细胞（Eos)、淋巴细胞均较正常组明显增高（P＜0．05）。体内应用TP可减少致敏大鼠BALF中Eos、淋巴细胞数目，同时可增加其BALF中淋巴细胞凋亡百分率。体外实际显示，不同剂量TP呈剂量依赖性（10^-7-10^5g/ml）的促进OVA抗原刺激的脾淋巴细胞凋亡，该效应随作用时间凋亡，可能是其抗炎机制之一，并可能是通过Fas/FasL途径发挥作用；同时TP可明显增加DXM的促淋细胞凋亡作用。为阐明TP对抗哮喘气道炎症的作用机制和探讨激素依赖性哮喘治疗的新途径提供了有意义的实验资料。

Effects of Triptolide on the apoptosis of lymphocytes in sensitized rats

Objective　To assess the influence of triptolide (TP) on apoptosis of lymphocyte in sensitized rats in vivo and in vitro. Methods　The rat model of allergic airway inflammation was established by first sensitizing followed by challenging the animals with ovalbumin (OVA). The animals were randomly divided into control group, sensitized group, and sensitized and TP-treated group. By using the techniques of morphology, terminal deoxynucleotidyl transferase nick and labeling (TUNEL) DNA gel electrophoresis and immunohistochemical staining, the influence of TP on lymphocyte apoptosis was observed. Results　In vivo experiments showed that the percentage of eosinophil (20.24±1.63%) and the percentage of lymphocytes (15.61±2.105%) in BALF in sensitized rats were significantly increased when compared with normal control (P<0.01). In TP-treated group, the numbers of both Eos and lymphocytes were significantly decreased, while the apoptosis percentage of lymphocytes in bronchoaloveolus lavage fluids (BALF) in the TP-treated group was higher than that in the sensitized group. In vitro experiments showed that TP (10-7-10-5g/ml) could promote the spleen lymphocyte to undergo apoptosis and expression of Fas/FasL when stimulated with OVA and this induction was does- and time-dependent to TP. DNA “ladder” formation in gel electrophoresis as well as apoptosis cells were found with typical morphologic characteristics. 10-7g/ml TP significantly increased the dexamethasone (DXM) promoted apoptosis percentage and expression Fas/FasL. Conclusions　TP could induce apoptosis of spleen and lung lymphocytes in sensitized animals, which may be mediated by Fas/FasL system so that it may be one of its anti-inflammation mechanisms. Besides, TP could work in coordination with DXM to induce apoptosis of lymphocytes. This study is conducive for the investigation of new therapeutic approaches.