D-氨基半乳糖/脂多糖诱导急性肝衰竭大鼠肝细胞凋亡的电镜观察

目的通过透射电镜观察急性肝衰竭大鼠肝脏超微结构,以了解肝细胞凋亡的形态学变化。方法给予雌性Wistar大鼠D-氨基半乳糖/脂多糖联合腹腔注射,计算其死亡率及生存时间,动态观察给药后4、8、12小时肝功能和组织病理学变化,并以TUNEL法检测和电镜观察原位细胞凋亡。结果实验组80%大鼠死于急性肝衰竭,平均生存时间为15.6±1.8小时。给药后4小时电镜观察,发现肝细胞线粒体肿胀、内质网扩张,胞浆包含体形成,部分细胞核呈早期凋亡表现,细胞内凋亡小体形成;8小时时,肝细胞凋亡明显增多并呈不同阶段表现,凋亡肝细胞内线粒体病变程度不一;TUNEL检测给药后8小时肝细胞,凋亡指数达高峰,与电镜观察结果一致。结论肝细胞凋亡为D-氨基半乳糖/脂多糖致急性肝衰竭大鼠肝细胞的主要病理形态学表现,这可能为该类型肝衰竭的主要病理学变化基础。

Electron microscopic observation of hepatocyte apoptosis in D-galactosamine/lipopolysaccharide-induced acute liver failure in rats

Objective To investigate the hepatocyte apoptosis in rats with acute liver failure. Methods Acute liver failure was induced by D-galaetosamine/lipopolysaccharide intraperitoneal injection in Wistar rats. Ten rats were sacririced at 4,8,and 12 hours,respectively,and the cell apoptosis was detected by tunnel assay. Ultrastructural changes were observed. Results 80% of rats with acute liver failure died from liver failure,and the mean survival time was 15.6±1.8 hours. The ultrastructural changes at 4 hours included swollen mitochondria,enlargement of endoplasmic retieulum,cytoplasmic inclusion bodies,condensation and margination of chromatiu,as well as characteristic formation of intracellular apoptotie bodies. Hepatocyte apoptosis became significant at 8 hours after treatment,with different mitochondrial changes. Index of apoptosis was significantly higher at 8 hours in accordance with electronic microscopic observation. Conclusions In rats with D-galactosamine/lipopolysaccharide-induced acute liver failure,hepatocyte apoptosis represents the predominant histopathology. Transmission electronic microscopy may help to illustrate morphologic changes in apoptotic cells.