实验性脂肪性肝病大鼠肝细胞凋亡与组织病理的对比研究

Comparative study of apoptosis and pathologic change in liver of rat with experimental fatty liver

目的 研究细胞凋亡在实验性脂肪性肝病大鼠病理机制中的作用。方法 40只Wister大鼠随机分为正常对照组 (A组 )、酒精组 (B组 )、高脂组 (C组 )和酒精加高脂 (D组 )四组 ,每组 10只大鼠。16周断头处死 ,取肝组织标本 ,分别以HE、SudanⅣ、Masson三色染色观察肝组织光镜下的病理改变 ,进行量化评定 ,同时在电镜下观察其超微结构的变化。用TUNEL法观察各组大鼠肝细胞凋亡的发生及其程度 ,并与肝组织病理改变进行对比分析。结果 模型组大鼠肝组织均表现有不同程度的脂肪变性、炎症、坏死和纤维化 ,以D组病理损害最重。各模型组大鼠肝细胞凋亡指数明显增高 ,尤以D组最为明显 ,模型组肝细胞凋亡指数与肝组织炎症评分、纤维化程度正相关 ,与其脂变程度无关。结论 不论是酒精或是高脂所致的脂肪性肝病大鼠 ,其肝细胞凋亡显著增加 ,并与肝组织炎症、坏死和纤维化改变正相关。说明肝细胞凋亡是脂肪性肝病病理变化的重要机制之一。

Objective To study the role of apoptosis of rat liver cell in the pathologic mechanism of fatty liver disease (FLD).Methods 40 Wistar rats were randomly divided into 4 groups:control group (group A),alcohol group (group B),fat-rich diet group (group C),alcohol and fat-rich diet group ( group D).There were 10 rats in each group.The rats were killed on the 16th week,the livers were collected for observing pathologic changes under microscope stained by HE,Sudan Ⅳ and Masson,and the result was analyzed by image quantitative analysis technique.The changes of ultrastructure also were checked under electron microscope.The apoptosis in rat liver cells was detected by TdT-mediated x-dUTP nick end labeling (TUNEL),and the correlation between apoptosis and pathologic change was analyzed.Results The rat livers presented the steatosis,inflammation, necrosis and fibrosis the severest in group D.The apoptosis indexes were increased significantly in every model group,the highest value was found in group D.The apoptosis index related positively to inflammation,necrosis and fibrosis of rat liver,however,which didn't to steatosis of liver in model group.Conclusion In spite of etiological factors,the apoptosis index is increased in rat liver of FLD model,which correlates positively with inflammation,necrosis and fibrosis of rat liver.The study proves that apoptosis plays an important role in pathologic mechanism of fatty liver disease.