中文摘要：

目的探讨ABCG2／Bcrp1基因在大鼠肝脏卵圆细胞中的表达及意义。方法建立大鼠2-乙酰氨基芴／三分之二肝切除模型，二步胶原酶灌注结合Percoll密度梯度离心分离大鼠肝脏卵圆细胞，采用荧光定量PCR技术检测ABCG2／Bcrp1基因在大鼠肝脏卵圆细胞和肝细胞中的表达水平，免疫组织化学、免疫荧光双标染色和Westernblot方法检测该转运蛋白的表达。结果大鼠肝卵圆细胞中ABCG2／Bcrp1基因的表达水平是肝细胞的13．8倍，ABCG2／Bcrp1蛋白相对分子质量大小为72000，定位于卵圆细胞膜。其表达位于门脉区周围，并向肝小叶延伸。免疫荧光双标染色显示与OV-6共表达。结论大鼠肝卵圆细胞表达高水平的ABCG2／Bcrp1，后者参与肝干细胞免受外源性化学物质损伤的自我保护机制。　

英文摘要：

Objective To investigate the expression of ATP-binding cassette superfamily G member 2 （ABCG2）/breast cancer resistance protein 1 （Bcrp1） transporter gene in hepatic oval cells of rats. Methods Rat 2/3 hepatectomy ＋ 2-acetylaminofluorene model was established to activate hepatic oval cells. By using selective enzymatic digestion and density gradient centrifugation, the hepatic oval ceils were isolated and identified by their morphological characteristics and phenotypic properties. The expression of ABCG2/Bcrp1 transporter gene was determined by quantitative real time reverse transcription-polymerase chain reaction was detected in isolated hepatic oval cells and hepatocytes. The expression of ABCG2/Bcrp1 transporters in rat liver tissues was determined by immunohistochemistry, cortfocal double-fluorescence immunostaining and Western blotting in hepatic oval cells. Results mRNA expression of the gene encoding ABCG2/Bcrp1 was increased up to 13.8 folds in hepatic oval cells compared to that in the rat hepatocytes. Immunohistochemical staining in rat liver samples demonstrated that the expression of ABCG2/Bcrp1 protein located on cell membranes was found around periportal areas ,extending to the hepatic lobules and simultaneous co-expression with OV-6. The molecular weight of ABCG2/Bcrp1 protein was 72KD determined by western blot. Conclusion Hepatic oval cells express high levels of active ABCG2/Bcrp1 gene which may has a cytoprotective role of hepatic oval cells in conditions of severe hepatotoxicity.