Suzuki T, Furusato M, Takasaki S, Shimizu S, Hataba Y
Cell Tissue Res. 1977 Sep 5;182(4):441-53. doi: 10.1007/BF00219828.
In order to obtain direct morphological information about the three-dimensional fine structure of the splenic terminal vascular bed, especially the terminating mode of the cordal capillaries, stereoscopic scanning electron microscopy of perfusion-fixed and freeze-fractured red pulp of a normal dog spleen was undertaken. An improved method of perfusion-fixation was utilized in which the hydrostatic pressures of the splenic artery and vein were maintained at approximately the same levels as those in the living state. Stereoscopic observations of scanning electron micrographs clearly demonstrated the three-dimensional fine architecture of the splenic sinuses, the spongy cordal reticular tissue and the intracordal vasculature. The cordal capillaries terminate in the labyrinthine cordal space according to a certain mode in which the walls of the terminals are transformed into a meshwork structure continuous with the cordal reticular tissue owing to an increase in number and size of fenestrations. No evidence could be detected to prove or suggest any direct continuity of the capillary end with the splenic sinus. These results strongly support the concept of an "open circulation", at least in the red pulp of the dog spleen, with the possibility of a "functionally closed circulation" under some physiological conditions.
为了获取有关脾终末血管床三维精细结构的直接形态学信息，尤其是索状毛细血管的终末方式，对一只正常犬脾脏经灌注固定和冷冻断裂的红髓进行了立体扫描电子显微镜观察。采用了一种改进的灌注固定方法，使脾动脉和静脉的流体静压维持在与活体状态大致相同的水平。对扫描电子显微镜照片的立体观察清楚地显示了脾窦、海绵状索状网状组织和索内脉管系统的三维精细结构。索状毛细血管以一定方式终止于迷宫样的索状间隙，其末端壁因窗孔数量和大小增加而转变为与索状网状组织连续的网状结构。未发现任何证据证明或提示毛细血管末端与脾窦有任何直接连续性。这些结果有力地支持了“开放循环”的概念，至少在犬脾脏红髓中是如此，并且在某些生理条件下可能存在“功能上封闭的循环”。
