肝硬化大鼠小肠黏膜形态结构改变与内毒素血症

Morphological structure changes of small intestinal mucosa and plasma endotoxin in cirrhotic rats

目的研究药物和胆汁淤积引起的肝硬化大鼠小肠黏膜形态结构改变和血浆内毒素水平。方法分别以硫代乙酰胺(TAA)(n=10)诱导和行胆管结扎术后(BDL)(n=7)的肝硬化大鼠为模型组,另以正常大鼠(n=12)作为正常对照组,分别观察光镜和透射电镜下小肠黏膜的形态,并采用鲎试剂基质显色法测定腹主动脉血浆内毒素含量。结果光镜下观察到模型组肝硬化大鼠小肠肠黏膜绒毛稀疏、萎缩,上皮细胞坏死,黏膜水肿伴有炎性细胞浸润;电镜下观察到模型组大鼠小肠壁超微结构有明显改变,肠黏膜绒毛破坏,减少,变短,倒伏,缺失,肠黏膜紧密间隙增宽,肠黏膜杯状细胞分泌减少,肠黏膜上皮细胞内线粒体和内质网肿胀。正常对照组大鼠的小肠黏膜绒毛形态及超微结构没有明显改变。模型组大鼠的血浆内毒素水平明显高于正常对照组(P<0.01)。结论模型组肝硬化大鼠都存在小肠黏膜结构的改变和内毒素水平的增高,提示肝硬化大鼠小肠黏膜的损伤与肠源性内毒素血症密切相关。

Objective To explore morphological structure changes of small intestinal mucosa and plasma endotoxin in cirrhotic rats. Methods Cirrhotic rats were induced by TAA and bile duct ligation. The healthy rats were enrolled as normal control group. Morphological structure changes of small intestinal mucosa were observed by light microscopy and transmission electron microscopy and plasma endotoxin in the abdominal aorta was measured with limilus lysate test. Re- suits Small intestinal villi in model group were injured under light microscopy, including reduced and atrophied mi- crovilli on the cells of intestinal mucosa, necrosis of the epithelial cell, and mucosal swelling with infiltrating of inflam- matory cell. Ultrasturctural changes of small intestinal mucosa occurred in the model group under electronic microscopy, including injured microvilli, wider gap of tight junction and the tumefaction of mitochondrion and endoplasmic reticu- lum. But there was no obvious change in normal rats. Plasma endotoxin level in model group rats was significantly higher than that in the normal control group. Conclusion It is suggested that cirrhotic rats have significantly changed morpho- logical structure and higher plasma endotoxin, the injury of small intestinal mucosa may be closely related with intestinal endotoxemia in cirrhotic rats.