Bouwens L, De Bleser P, Vanderkerken K, Geerts B, Wisse E
Laboratory of Cell Biology and Histology, Free University Brussels, Belgium.
Enzyme. 1992;46(1-3):155-68. doi: 10.1159/000468782.
The normal hepatic sinusoid is formed or lined by four different cell types, each with its specific phenotypic characteristics, functions and topography. Endothelial cells constitute the closed lining or wall of the capillary. They contain small fenestrations to allow the free diffusion of substances, but not of particles like chylomicrons, between the blood and the hepatocyte surface. This filtering effect regulates the fat uptake by the liver. Sinusoidal endothelial cells also have a pronounced endocytotic capacity which makes them an important part of the reticuloendothelial system. They are also active in the secretion of bioactive factors and extracellular matrix components of the liver. Recently, a zonal heterogeneity of the endothelial lining has been reported with regard to its filtering capacity (fenestration) and binding capacity for lectins and cells. Kupffer cells are intrasinusoidally located tissue macrophages with a pronounced endocytotic capacity. They are potent mediators of the inflammatory response by the secretion of a variety of bioactive factors and play an important part in the immune defense. A zonal heterogeneity has been established with regard to the endocytotic capacity and cytotoxic function. Pit cells are now known to represent a liver-associated population of large granular lymphocytes. They have the capacity to kill tumor cells and probably also play a role in the antiviral defense of the liver. In addition, pit cells may have a growth-regulatory function of the liver. They are known to be numerically more prominent in the periportal region, as is also the case for Kupffer cells. Fat-storing or Ito cells are present in the perisinusoidal space of Disse and are thought to represent the main hepatic source of extracellular matrix components. They are also the main site of vitamin-A storage. Fat-storing cells are more numerous in the periportal region than in the central region of the hepatic acinus. The periportal cells also store higher amounts of vitamin A. Sinusoidal cells may be considered to represent a functional unit at the border line between the hepatocytes or parenchymal cells and the blood. They participate in various liver functions and liver pathologies and our knowledge about this is growing. The heterogeneity of these cell types and possible cooperations between them and the hepatocytes may add to our understanding of liver functions.
正常肝血窦由四种不同类型的细胞构成或排列，每种细胞都有其特定的表型特征、功能和分布位置。内皮细胞构成毛细血管的封闭内衬或壁。它们含有小窗孔，允许物质在血液和肝细胞表面之间自由扩散，但不允许乳糜微粒等颗粒通过。这种过滤作用调节肝脏对脂肪的摄取。肝血窦内皮细胞还具有显著的内吞能力，使其成为网状内皮系统的重要组成部分。它们在肝脏生物活性因子和细胞外基质成分的分泌中也很活跃。最近，已报道内皮内衬在过滤能力（窗孔）以及对凝集素和细胞的结合能力方面存在区域异质性。库普弗细胞是位于肝血窦内的组织巨噬细胞，具有显著的内吞能力。它们通过分泌多种生物活性因子，是炎症反应的有效介质，在免疫防御中起重要作用。在吞噬能力和细胞毒性功能方面已确定存在区域异质性。贮脂细胞或伊托细胞存在于狄氏间隙的肝血窦周隙中，被认为是细胞外基质成分的主要肝脏来源。它们也是维生素A储存的主要部位。贮脂细胞在门静脉周围区域比肝腺泡中央区域更多。门静脉周围的细胞也储存更多的维生素A。肝血窦细胞可被视为肝细胞或实质细胞与血液之间边界线上的一个功能单位。它们参与各种肝脏功能和肝脏病理过程，而且我们对此的了解正在不断增加。这些细胞类型的异质性以及它们与肝细胞之间可能的协作，可能会增进我们对肝脏功能的理解。
