Non-invasive, three-dimensional analysis of hepatic lobular microcirculation.

肝脏微循环是为肝细胞和肝窦细胞提供氧气和营养物质以及清除废物的基本系统。为阐明肝脏微循环在肝病发生发展中的作用，在装有灵敏摄像机和计算机图像处理系统的活体显微镜下，对肝脏血管和细胞的三维结构及其功能进行了研究。用一系列技术研究了各种外源性、血管活性物质和毒性物质的动态反应。结果如下：1)门脉周围区血窦曲折，形成三维网络，红细胞血流速度较中心周区慢。中心周围的血窦较宽，平行走行，汇聚成小静脉。中心周围血流速度明显快于门脉周围，且与血管直径呈正相关。因此，门静脉周围是毛细血管的微循环特征，而中心周围是静脉的微循环特征。2)门静脉末端和肝末端小静脉的三维结构显示，门静脉末端小静脉到肝表面的距离大于末端小静脉到肝表面的距离。3)利用SIT摄像机和视频处理系统构建了活体荧光显微镜系统。分析荧光素从门静脉周围到中心周围血窦和肝细胞的转运以及从肝细胞到胆小管的转运。正常肝细胞摄取均匀，胆小管网络呈多角形，而CCl4处理的大鼠肝细胞摄取和分泌明显不均一，这取决于细胞损伤和微循环障碍。

Hepatic microcirculation is fundamental system for supplying the oxygen and nutrients to the hepatocytes and sinusoidal cells and for removal of waste matters. For clarifying the role of hepatic microcirculation in patho-genesis and developement of liver diseases, three-dimensional structure of vessels and cells and their functions were studied by in vivo microscope equipped with a sensitive camera and computerized image processing system. Dynamic responses to various exogenous, vasoactive and toxic substances were also investigated by a series of techniques. The findings were as follows:1) In periportal area, the sinusoids were tortuous and formed 3-dimensional networks, the red blood cell flow velocity was slower than in the pericentral area. The sinusoids around the pericentral region were wider, ran parallelly and converged to venules. The velocity around pericentral area was much faster than in periportal area and was positively correlated with the diameter of the vessels. Thus, periportal sinusoids were microcirculatory characteristic of the capillary, while pericentral sinusoids were of the venules.2) The three dimensional structures of the terminal portal and terminal hepatic venules have shown that the distance between the terminal portal venule and the liver surface was larger than that between the terminal hepatic venule and liver surface.3) In vivo epifluorescent microscope system was constructed using SIT camera and videoprocessing system. Transport of fluorescein from periportal to pericentral sinusoids and hepatocytes and from hepatocytes to bile canaliculi were analyzed. A homogeneous uptake by normal hepatocytes and polygonal appearance of bile canalicular network were observed, while in CCl4-treated rats, a marked heterogeneous uptake and secretion were observed, depending on cell damage and microcirculatory disorder.