内毒素诱发肝性脑病大鼠脑超微结构观察

摘要

目的：观察内毒素诱发肝硬化大鼠发生肝性脑病时血脑屏障超微结构变化。方法：用小剂量内毒素(3 mg／kgBW)一次性腹腔内注射诱发肝硬化大鼠发生肝性脑病。取部分大脑皮层组织制备超薄切片，在电子显微镜下观察其超微结构变化。结果：肝性脑病大鼠脑微血管明显扩张，内皮皱折增多，内皮下基底膜电子密度降低，甚至局部溶解消失。微血管周围星状胶质细胞突起及皮层内胶质细胞明显肿胀，细胞器成分减少，基质解聚。结论：内毒素诱发肝性脑病时，脑超微结构确有明显变化。这些变化提示，肝性脑病发生时，血脑屏障通透性增加；同时，脑胶质细胞呈现水肿。内毒素血症有可能是各种肝性脑病发生机制学说的共同基础。%Objective: The cerebral ultrastrunctural changes of hepatic encephalopathy(HE) in cirrhoticrats induced by endotoxin injection were investigated. Methods: Hepatic encephalopathy wereprecipated by endotoxin injection peritoneally into the cirrhotic rats( 3 mg/kg BW). The ultra-thin section from the cerebral cortex tissue were prepared and observed under electron mi-croscopy. Results: The mini blood vessels in the cortex of HE rats were expanded. There was anincrease of the cytoplasm folds of endothelium. The basement membrane under endothelial cellsshowed decreased electronic density or local degradation. The astrocytes and their processesaround mini blood vessels expressed a varity of edema, there was a decrease of cytoplasmic or-ganells and appearenee of matrix degradation. Conclusion: There are obvious changes in the cere-bral ultrastruncture in HE induced by endotoxin injection into cirrhotic rats. The changes implythat the there is a increased permeability of blood-brain barrier(BBB) in HE. Meantime, the glialcells show edema. The development of endotoxemia in HE may be the common base of all kindsof hypothesis about the pathogenesis of HE.