血吸虫病肝硬化兔肠粘膜屏障功能损害及与内毒素血症的关系

目的:研究血吸虫病性肝硬化兔肠粘膜屏障功能的改变及与内毒素血症的关系。方法:50只雄性大耳白兔,按编号法随机分为正常组(n=10)及感染组(n=40)。感染组采用腹部敷贴法感染日本血吸虫尾蚴,分别于感染后12周(12W组,n=20)、20周(20W组,n=20):(1)测定各组血浆内毒素和肠粘膜通透性指标FITC-D含量;(2)取回盲段小肠组织行HE、Masson染色和电镜观察;(3)取肝、脾、肾和肠系膜淋巴结匀浆进行细菌培养,计算细菌易位率;(4)免疫组化法测定小肠粘膜上皮细胞紧密连接蛋白(Occludin)表达水平。结果:12W、20W组血浆FITC-D和内毒素含量明显高于正常组(P<0.01),且20W组高于12W组(P<0.01);12W组、20W组小肠黏膜上皮细胞微绒毛明显缩短、稀疏、部分断裂、扭曲、倒伏、脱落,肠上皮细胞间紧密连接结构模糊,细胞间隙增大,线粒体基质减少,部分嵴断裂,粗面内质网肿胀,结构不清;12W组及20W组细菌易位率较正常组明显增高(P<0.01);正常组肠粘膜上皮细胞表面及胞质内均见Occludin蛋白显著表达,12W组和20W组较正常组表达减弱(P<0.01),且20W组更弱(P<0.05)。结论:血吸虫病性肝硬化兔随着肝脏损害加重,出现明显肠粘膜屏障功能障碍和肠源性内毒素血症,肠道通透性升高与内毒素水平明显正相关,可能是是肠源性内毒素血症产生的重要原因之一。

Study of the Relations between Intestinal Mucosal Barrier Dysfunction and Endotoxemia in Rabbits with Cirrhosis

Objective: To investigate the relations between intestinal mucosal barrier dysfunction and endotoxemia in rabbits with cirrhosis caused by schistosomiasis. Method: Total 50 male rabbits were involved in this study. The animals were randomly divided into normal group and infection group. Cirrhosis were caused by infection of schistosomiasis. Randomly selected 20 rabbits respectively from the infected group 12W, 20W later after infection as 12W group, 20W group. The whole blood, tissue of liver, spleen, kidney together with mesenteric lymph nodes were collected to make germiculture and measure the bacterial translocation. The ultrastructure of intestinal epithelial tight junction in the small intestine and the intestinal villi were observed by electron microscope.The transmembrane binding protein (occludin) levels in terminal ileum were detected by immunohistochemistry method. Also, the plasma endotoxin was measured. Results: The translocation of bacteria was found in group 12W and 20W group Plasma FIFC-D and endotoxin in 12W group and 20W group were significantly increased than normal group(P<0.05). The control group rabbits’ small intestine ultrastructure was normal; but those of 12W group and 20W group, intestinal mucosal epithelial cell microvilli obviously shortened, sparse, part of them fractured, distorted intrafamilial communication, lodging, shedding, tight junctions between cells tructure fuzzy, cell gap increased, the mitochondrial matrix reduced, partial crista fragmented, rough endoplasmic reticulum swelled, structure is unclear according to the express of occludin, it had a noted decrease in 12W group and 20W group than that of normal group (P<0.01). 20W group and 12W group also had significant differences. Conclusion: Schistosomiasis cirrhosis rabbits with liver damage increased, intestinal mucosa barrier function and the enterogenous endotoxemia appeared. Elevated intestinal permeability is one of the important causes of enterogenous endotoxemia.