刀豆蛋白A注射不同时间后自身免疫性肝炎小鼠肝脏的形态学和功能变化

Morphological and functional changes of liver in mice with autoimmune hepatitis after injection of concanavalin A at different times

目的观察尾静脉注射刀豆蛋白A(ConA)后不同时间内小鼠肝脏的形态学变化及转氨酶含量变化,从形态学和血清学角度探讨自身免疫性肝炎(AIH)的发病机制。方法昆明小鼠随机分为正常对照组、6 h组、12 h组、24 h组、48 h组以及1周组,每组6只。各实验组小鼠按15 mg/kg体质量尾静脉注射ConA(正常对照组尾静脉注射0.9%氯化钠注射液),分别于不同时间点处死。小鼠处死前采用"摘除眼球法"取血,并常规制备血清。无菌条件下提取小鼠肝脏,部分4%多聚甲醛内固定,部分-80℃保存备用。采用酶标仪检测血清中丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)含量,肝脏常规石蜡包埋、切片,并进行苏木精-伊红(HE)染色。结果小鼠血清ALT在ConA诱导AIH后6 h达峰值,后逐渐降低;而血清AST在发病24 h后达峰值。小鼠肝组织HE染色结果显示,在AIH 6 h组和12 h组,小鼠肝小叶中央静脉周围可见不同程度淋巴细胞浸润;AIH 24 h组可见小叶中央静脉周围及肝血窦内淋巴细胞浸润增多;AIH 48 h组可见肝小叶内出现不同程度的界板状坏死灶;而在AIH 1周组肝小叶呈弥漫性肝细胞水肿和坏死表现。结论 AIH小鼠肝脏病变呈时序性特征,建立AIH小鼠模型时,可根据实验目的不同选择不同的ConA诱导时间。

Objective To observe the morphological changes and serum transaminase levels in mice at different time after injection of concanavalin A(ConA)viathe tail vein,and to investigate the pathogenesis of autoimmune hepatitis(AIH)from the morphological point of view.Methods Kunming mice were randomly divided into normal control group,6 h group,12 h group,24 h group,48 h group and 1 w group,with 6 rats in each group.The mice in each experimental group were injected with ConA(normal saline in the control group)at a dose of 15 mg/kg body weight,and sacrificed at different time points.Before the mice were sacrificed,blood was taken by"eye removal method",and serum was routinely prepared.The liver of the mice was extracted under aseptic conditions,partially fixed in 4%paraformaldehyde,and stored at-80℃for later use.Serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)were detected by ELISA.The liver was embedded in paraffin,sectioned,and stained with HE.Results The serum ALT of mice increased significantly at 6 h after ConA induced AIH,and then decreased gradually.Serum AST increased significantly after 24 h of onset,and then decreased gradually.Hepatic HE staining showed that lymphocytes infiltrated around the central lobule of the hepatic lobules in the AIH 6 h and 12 h groups.In the AIH 24 h group,lymphocytes infiltration around the central venule and hepatic sinusoids were observed.In AIH 48 h group,the lobular necrosis of the hepatic lobule was observed.In the AIH 1 w group,the hepatic lobules showed diffused hepatocyte edema and necrosis.Conclusion The liver lesions of AIH mice are characterized by time series.When establishing the AIH mouse model,different ConA induction times can be selected according to the purpose of the experiment.