猫儿山小鲵肝的组织结构

通过常规石蜡切片技术对2例猫儿山小鲵（Hynobius maoershanens）肝进行组织学观察。结果显示，猫儿山小鲵肝分为两叶，右叶稍大于左叶。肝组织结构主要由被膜、中央静脉、门管区和肝细胞组成。门管区的小叶间静脉和小叶间胆管清晰可见，但小叶间动脉不易观察。肝内结缔组织少，肝小叶之间界限不清。肝细胞索围绕中央静脉呈放射状排列，但放射状不明显。肝实质中含有大量清晰可见的棕黑色色素团，可能与此物种对低氧环境的适应有关。

Histological Structure of the Liver in Hynobius maoershanensis

Hynobius maoershanens belongs to Hynobiidae, and is endemic to Maoershan Natural Reserve in Guangxi Province, China. It is restrictedly inhabited in alpine swamp at an altitude of 2,000 m with a small population size. We investigated the histological structure of liver, using anatomical methods and paraffin sectioning technique. The total length, head length, head width, tail length, body weight and liver weight were measured. An Olympus BX-63 automatic fluorescence microscope was used to analyze the liver histological structure. The results showed that the histological structure of the liver in H. maoershanensis was similar to that of other amphibians, which could be divided into the right and left lobe (Fig. 1a). Glisson capsule, central veins, portal areas and hepatic cells constituted the liver structure (Fig. 2a, b). The hepatocyte cords were arranged in an indistinct radial pattern around the central vein (Fig. 2c, d). Moreover, interlobular veins, bile ducts in portal areas were clearly found (Fig. 2e). The boundaries of liver lobules were unclear due to the underdevelopment of connective tissues (Fig. 2c-g). Many brown-black melanin granules could be seen in liver parenchyma (Fig. 2a, b). Our findings suggest that the brown-black melanin granules in the liver parenchyma of H. maoershanensis might be an adaptation to the low-oxygen environment.