斑马鱼肝脏胆管系统的研究

目的系统地观察斑马鱼肝脏胆管系统的组织结构和超微结构。方法采用酶组织化学、免疫组织化学以及透射电镜技术。结果斑马鱼肝脏胆管系统在肝实质内呈树枝状分布。胆管系统由细胞内和细胞间毛细胆管、前胆小管，胆小管和胆管构成。细胞内毛细胆管起源于细胞核附近，并且存在向细胞表面迁移。在肝细胞之间，有一胞质少、细胞核呈狭长型的明显不同于肝细胞的细胞，此细胞为BP细胞，BP细胞通过紧密连接与肝细胞进行细胞间的通讯活动。前胆小管由BP细胞和肝细胞共同构成管道的管壁。胆小管管壁通常由2～4个上皮细胞构成，胆小管上皮细胞与肝细胞之间直接接触，并没有基底膜使之相隔。本实验通过透射电镜还观察到由一个上皮细胞质膜突起再内折形成的胆小管，并通过一个纵向的连接复合体密封管道。胆管的管壁上皮细胞由立方上皮细胞或柱状上皮细胞构成，胆管外有结缔组织环绕。此外，淋巴细胞也参与了胆管管壁上皮细胞的构成，表明胆管存在黏膜免疫的应答。前胆小管和胆小管是连接毛细胆管和胆管的部分，因此，本实验认为前胆小管和胆小管相当于哺乳动物的黑林管。Mg^2＋-ATP酶反应显示，胆管系统被染成棕黑色，交织成网。通过免疫组织化学的方法发现胆管系统的上皮细胞的胞体以及起源于这些细胞的胆汁管道也呈阳性。结论斑马鱼胆管系统不仅与哺乳类和鸟类有差异，而且与其他硬骨鱼类也不完全相同。

Research on Bile System in Zebrafish(Brachydanio rerio)

Objective To research on the intrahepatic biliary system in the zebrafish, Brachydanio rerio. Methods By using enzyme histochemical characterization, immunohistochemistry and electron microscopy. Results The biliary system was arranged in arborization in the parenchyma.The biliary tree included sequentially by intracellular and intercellular canaliculi, preductules,ductules and ducts. The intercellular originated at the neighborhood of the nucleus to extend to the cell surface where it emptied into the intra parenchymal biliary passage running in the interhepatocytic space. In the preductules, the wall was formed by bile preductular epithelial cells and hepatocytes ,The bile preductular epithelial cells were linked to hepatocytes by the tight junctions. The wall of the biliary ductule usually consisted integrally 2 to 4 biliary epithelial cells. These cells had no basal lamina and were contacted with hepatocytes directly. A ductule that was composed of a single cell and was embedded between two adjoining liver cells was found by TEM. The lumen of this ductule was very narrow and formed by the infolding of the plasma membrane of the ductule cell. The wall of bile ducts was composed of cuboidal epithelial cells, and the bile duct was encircled by the connective tissue. Whereas in ducts, apart from those cells, there were intraepithelial lymphocytes.This suggested that there exited mucosal immune response. The preducules and ductules formed a segment connecting canaliculi to ducts, thus, we considered that segment as being analogous to the mammalian canals of Hering.The reactions for Mg^2＋-dependent ATPase showed that bile tree was strained brownish-black color and interwove into a network. The bile system was revealed by immunstaining with a monoclonal antibody 2F11 that detected biliary epithelial cell bodies which are distributed scatteredly in interhepatocytic and the proximal regions of the ducts arising from these cells was stained. Conclusions The bile systerm in zebtafish is not only different with the mammals and birds, but also with other bony fish.