目的　探讨幼鼠肠缺血再灌注 (I/R)下免疫器官凋亡的发生及分子病理学机制。方法32只雄性Wistar大白鼠随机分成 4组 :生理对照组、麻醉组、假手术组、缺血再灌注组。用电镜、TUNEL法 (TdT介导的dUTP末端缺口标记是一种检查细胞凋亡的方法 ,一般采用半定量方式计算结果。检测免疫器官凋亡的发生 ;原位杂交方法检测Fas(凋亡因子 ) /Fas LmRNA的表达。结果　脾脏主要在红髓内存在凋亡 ,淋巴结主要在髓窦内存在凋亡 ,凋亡指数从 1～ 4组逐渐升高 ,除 1、2组外 ,各组差异均有显著性意义。胸腺内存在Fas/Fas L的表达 (Fas L是Fas的配体 ,Fas与Fas L结合 ,可以引起有Fas表达的细胞凋亡。) ,但表达量极少 ;脾脏Fas表达明显高于Fas L ;淋巴结Fas L表达明显高于Fas,表达量从 1～ 4组逐渐升高 ,除 1、2组外 ,各组差异均有显著性意义。结论　①在幼鼠肠I/R早期 ,脾主要以增加Fas的表达引发凋亡 ,肠系膜淋巴结主要以增加Fas L的表达引发凋亡 ;②在幼鼠肠I/R早期 ,可能通过影响外周免疫器官巨噬细胞及淋巴细胞的凋亡 ,影响免疫功能状态 Objective To investigate the occurrence and molecular pathological mechanism of immune organ apoptosis in neonatal rat with intestinal ischemia-reperfusion (I / R). Methods Thirty-two male Wistar rats were randomly divided into 4 groups: control group, anesthesia group, sham operation group and ischemia-reperfusion group. Electron microscopy, TUNEL method (TdT-mediated dUTP nick end labeling is a method of apoptosis detection, the results are generally used semi-quantitative methods to detect the occurrence of immune organ apoptosis; in situ hybridization method to detect Fas (apoptosis factor ) / Fas LmRNA expression.Results The spleen mainly existed in the red pulp of the apoptosis, the main lymph node apoptosis in the sinusoid, apoptotic index gradually increased from 1 to 4 groups, except 1, 2 groups, the difference between the groups There was significant expression of Fas / Fas L in the thymus (Fas L is a ligand of Fas, which combined with Fas L can induce apoptosis of Fas-expressing cells) The expression was significantly higher than that of Fas L, the expression of Fas L in lymph nodes was significantly higher than that in Fas, and the expression level was gradually increased from 1 to 4 groups except for group 1 and group 2. Conclusion ①In intestinal I / R early, the spleen mainly induces apoptosis by increasing the expression of Fas, and the mesenteric lymph node mainly induces apoptosis by increasing the expression of Fas L; ② In the early stage of intestinal I / R in young rats, it may affect the peripheral immune organ macrophages and lymphocytes Apoptosis, affecting immune function status