正常大鼠胆管细胞胆汁酸转运蛋白表达的异质性

目的检测正常大鼠肝脏不同部位胆管细胞胆汁酸转运蛋白表达的差异。方法用酶消化辅助机械分离方法获得SD大鼠胆管组织并分为大、小胆管组织,应用免疫组织化学、Real time PCR及Western blot等方法检测大鼠胆道系统顶侧钠依赖性胆汁酸转运体（ASBT）、回肠胆汁酸结合蛋白（IBABP）和基底侧有机溶质转运体α（OSTα）表达,分析其定位及分布的差异。结果 ASBT表达于胆管细胞顶侧胞膜,IBABP表达于细胞浆,Ostα表达于胆管细胞基底侧胞膜。ASBT和IBABP主要表达于大胆管上皮细胞,大胆管组织中ASBT和IBABP的表达量显著高于小胆管组织（P〈0.05）;而Ostα则同时表达于大胆管和小胆管上皮细胞,其表达量在大、小胆管组织中无显著差异（P〉0.05）。结论胆管细胞对胆汁酸的重吸收主要发生于大胆管。

The heterogeneous expression of cholangiocyte bile acid transports in normal rats

Objective To detect the different locations and distributions of bile acid transporters in the biliary system of normal rats.Methods Rat bile duct tissue was obtained using enzymatic digestion assisted with mechanical separation and divided into two groups：large and small bile duct tissue.Immunohistochemistry and Real time PCR,as well as Western blot,were used to detect the expression of apical sodium-dependent bile acid transporter（ASBT）,ileum bile acid binding protein（IBABP） and organic solute transporter alpha（OSTα） biliary system respectively.Results ASBT and IBABP were dominantly expressed on the large bile duct epithelial cells,while Ostα was expressed on both large and small bile duct.Moreover,the expression levels of ASBT and IBABP in large bile ducts were significantly higher than those in small bile ducts,while the expression levels of Ostα in large bile ducts were similar with those in small bile ducts.Conclusion The bile acid re-absorption may exclusively take places in large bile duct