Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002, Jiangsu Province, China.
Inflammation. 2012 Dec;35(6):1880-8. doi: 10.1007/s10753-012-9510-1.
The present study aimed to determine whether any specific intestinal site or intestinal mucosal inflammation is highly correlated with bacterial translocation (BT). Enterostomy tubes were surgically placed in adult male Sprague-Dawley rats 5 days before induction of experimental model. After surgery, sterile water containing kanamycin (25 mg/L) was injected into each intestinal segment through the tubes for 3 days. Green fluorescent protein (GFP)-transfected Escherichia coli (n = 30 for lipopolysaccharide (LPS) group, and n = 30 for control group) or 0.9 % saline (n = 30 for blank group) were injected into each intestinal segment through the tubes for two consecutive days. Rats were then subjected to LPS-induced endotoxemia; lactulose and mannitol were injected into each intestinal segment through the tubes simultaneously. At 6 h after LPS injection, BT to distant organs and integrity of tight junctions (TJ) were examined by fluorescence and electron microscopy, respectively. The urinary excretion ratio of lactulose/mannitol (L/M) and intestinal mucosal cytokine levels were assessed. We found that the intestinal permeability, reflected by translocation rates of GFP-labeled E. coli, the levels of open TJ, the excretion ratio of L/M, and the inflammatory cytokine levels were higher in the LPS group than in the control and blank groups. The endotoxemia ileum showed the highest levels of both intestinal permeability and inflammatory cytokine, while the colon showed the lowest. The present study of endotoxemia rats suggests that LPS increases gut paracellular permeability and induces BT. The ileum is the site of greatest BT risk, while the colon is the lowest, and the difference in risk between these sites is correlated with intestinal mucosal inflammation.
本研究旨在确定特定的肠道部位或肠道黏膜炎症是否与细菌易位（BT）高度相关。在诱导实验模型前 5 天，通过手术将肠造口管放置在成年雄性 Sprague-Dawley 大鼠体内。手术后，通过这些管子向每个肠道段注入含有卡那霉素（25mg/L）的无菌水，持续 3 天。通过这些管子向每个肠道段连续两天注入 GFP 转染的大肠杆菌（LPS 组 n=30，对照组 n=30）或 0.9%生理盐水（空白组 n=30）。然后，大鼠接受 LPS 诱导的内毒素血症；通过这些管子同时向每个肠道段注入乳果糖和甘露醇。在 LPS 注射后 6 小时，通过荧光显微镜和电子显微镜分别检查 BT 到远处器官和紧密连接（TJ）的完整性。通过评估乳果糖/甘露醇（L/M）的尿排泄比和肠道黏膜细胞因子水平来评估肠道通透性。我们发现，通过 GFP 标记的 E. coli 易位率、开放 TJ 的水平、L/M 的排泄比和炎症细胞因子水平来反映的肠道通透性，在 LPS 组比对照组和空白组更高。内毒素血症回肠显示出最高的肠道通透性和炎症细胞因子水平，而结肠显示出最低的水平。本对内毒素血症大鼠的研究表明，LPS 增加肠道旁细胞通透性并诱导 BT。回肠是 BT 风险最大的部位，而结肠是风险最低的部位，这些部位之间的风险差异与肠道黏膜炎症相关。
