中文摘要：

目的：探讨低氧训练对大鼠小肠黏膜屏障功能的作用和机制。方法：5周龄雄性SD大鼠80只,随机分为常氧对照组（C组,n=20）、常氧训练组（E组,n=20）、低氧对照组（HC组,n=20）、低氧训练组（HE组,n=20）,通过人工低氧和游泳训练模拟高原训练,分别观察2周、6周后大鼠小肠黏膜的组织结构和超微结构,检测血浆中二胺氧化酶（DAO）、D-乳酸（D-La）以及肠组织中肿瘤坏死因子（TNF-α）、核因子-κB（NF-κB）的含量和小肠黏膜中紧密连接蛋白occludin mRNA的表达量。结果：（1）实验6周后,透射电镜观察显示,与常氧对照组相比,常氧训练组大鼠小肠微绒毛较稀疏,且排列不整齐,黏膜上皮细胞之间的间隙变宽,线粒体数量明显减少,嵴模糊;低氧对照组小肠微绒毛长度显著缩短,排列较为紊乱,黏膜上皮细胞之间的间隙变宽,少量线粒体变性;低氧训练组小肠微绒毛数量明显减少,长度明显缩短,肠绒毛出现倒伏,黏膜上皮细胞之间的间隙变宽,细胞结构不清晰,线粒体变性,部分线粒体嵴模糊、甚至消失。（2）2周后,运动训练可显著减少小肠绒毛数量（P〈0.01）,显著提高血浆DAO、D-La（P〈0.05）以及小肠组织中NF-κB含量（P〈0.01）;而低氧暴露可显著降低小肠组织occludin mRNA表达（P〈0.01）,显著提高血浆DAO、D-La（P〈0.05）以及小肠组织TNF-α（P〈0.05）、NF-κB（P〈0.01）含量;低氧暴露联合运动训练对进一步减少小肠绒毛数量、长度和occludin mRNA表达,升高血浆DAO、D-La以及小肠组织TNF-α、NF-κB含量均无显著的交互作用（P〉0.05）。（3）6周后,运动训练及低氧暴露均显著降低小肠绒毛数量（P〈0.01）,增加血浆DAO、D-La含量（P〈0.01）以及小肠组织中TNF-α（P〈0.01,P〈0.05）和NF-κB含量（P〈0.01）,显著降低小肠组织中occludin mRNA的表达（P〈0.05）;且低氧联合运动训练对进一步减少小肠绒毛?

英文摘要：

Objective To explore the effect of mucous membrane and underlying mechanism in ley rats were randomly divided into a control group and a hypoxia exercise group,each of 20. hypoxic training on the barrier function of intestinal rats. Methods Eighty 5-week-old male Sprague-Daw- group, an exercise training group, a hypoxia control The altitude training was conducted through swimmingtraining in artificial hypoxia environment. Two and 6 weeks after the intervention, the tissue structure and uhrastructure of small intestine mucosa were observed. The content of diamine oxidase （DAO）and D-lactate （D-LA）,tumor necrosis factor-α （TNF-α）and nuclear factor κB （NF-κB）in plasma and the mRNA level of occludin in ileal tissue were measured. Results （l）Electron microscopy data showed that, after six weeks, compared with the control group, the microvilli of rats in the exercise training group were sparser and arranged irregularly. Furthermore, the gap between epithelial cells became wid- er. In addition,the number of mitochondria decreased significantly and cristae were vague. For the hy- poxia control group,the microvilli shortened significantly and arranged irregularly. Moreover, the gap be- tween cells became wider with partial denatured mitochondria. For the Hypoxia exercise group,the num- ber of mucosa] epithelium microvilli in the bowels reduced significantly and the microvilli shortened sig- nificantly. Similar to that of the hypoxia control ,group, the gap between epithelium cells growed wider. However, the cellular structure were fuzzier, and the denature of mitochondria worsened, with the cristae being vague even disappearing partially. （2）Two weeks of exercise training reduced the number of in- testinal microvilli significantly （P〈0.01）,but increased the plasma level of the DAO and D-LA,as well as the expression level of NF-κB in intestinal tissue significantly （P〈0.05）. Hypoxic exposure signifi- cantly reduced the mRNA level of occludin in small intestine （P〈0.01）,but sign