幼鼠肠缺血再灌注损伤下免疫器官凋亡的分子病理学研究

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，各组差异增有显著性意义。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。

Apoptosis of immune organ during gut ischemia/reperfusion injury: a molecular study

Objective To examine the molecular changes in immune organs of immature rats during gut inschemia/reperfusion injury.Methods Thirty two male immature Wistar rats were divided randomly into four groups: 1) Physiological control group,2) Anesthesia control group,3) Sham control group and 4) Experimental group.Apoptosis in immune organs was assessed by electromicroscopy and TUNEL technique.The expression of Fas/Fas L mRNA in immune organ were assessed by in situ hybridization.Results Spleen apoptosis was located mainly in splenic sinus.Mesentery lymph node apoptosis was mainly seen in medullary sinus.There was significant increase of apoptosis in group III and IV.In thymus expression of Fas/Fas L mRNA was hardly detected.In spleen,the expression of Fas mRNA was higher than that of Fas L mRNA.In mesentery lymph,the expression of Fas L mRNA was higher than that of Fas mRNA.Conclusions 1) Fas expression is higher than that of Fas L in spleen.This implies increased Fas expression induces apoptosis in spleen.On the other hand,high Fas L expression in mesentery lymph node implies its role in apoptosis induction.2) In the earlier period of gut I/R,Fas/Fas L induced apoptosis in immune organs may affect the host immune status.