Takada K, Otsuki Y, Magari S
Department of Medicine, Osaka Medical College, Japan.
Lymphology. 1991 Sep;24(3):116-24.
The lymphatics and pre-lymphatic connective tissue of rabbit pericardium and epicardium were examined by light and electron microscopy under normal conditions and after the injection of India ink and latex particles into the pericardial cavity. A characteristic lattice structure of connective tissue was present between the small mesothelial cells and the submesothelial lymphatic capillaries in the basal region of the pericardium, but not in the epicardium. Milky spot-like structures bulging toward the pericardial cavity were found in the pericardium, similar to those in the omentum and mediastinal pleura. Within 60 minutes after injection, carbon and latex particles were directly absorbed through the intercellular clefts of the adjacent small mesothelial cells into the submesothelial layer particularly at sites of characteristic lattice structure. Carbon particles were already present in the lumens of lymphatic capillaries at this time. Macrophages in the pericardial cavity and submesothelial layers of the pericardium engulfed both carbon and latex particles. Our results suggest two possible routes of drainage of particulate matter from the pericardial cavity into the lymphatics: direct absorption and indirect absorption after phagocytosis by macrophages. Macrophages probably migrate from the milky spot-like structures described in this study. Epicardial lymphatics, in contrast, drain tissue fluid primarily from the myocardium.
在正常条件下以及向心包腔内注射印度墨汁和乳胶颗粒后，通过光学显微镜和电子显微镜对兔心包和心外膜的淋巴管及淋巴管前结缔组织进行了检查。在心包基底部的小间皮细胞与间皮下淋巴管之间存在一种结缔组织的特征性晶格结构，而在心外膜中则不存在。在心包中发现了向心包腔突出的乳斑样结构，类似于大网膜和纵隔胸膜中的结构。注射后60分钟内，碳和乳胶颗粒通过相邻小间皮细胞的细胞间隙直接被吸收到间皮下层，特别是在特征性晶格结构部位。此时碳颗粒已存在于淋巴管腔内。心包腔和心包间皮下层的巨噬细胞吞噬了碳和乳胶颗粒。我们的结果提示了颗粒物质从心包腔进入淋巴管的两种可能途径：直接吸收和巨噬细胞吞噬后的间接吸收。巨噬细胞可能从本研究中描述的乳斑样结构迁移而来。相比之下，心外膜淋巴管主要引流来自心肌的组织液。
