Linck G, Porte A
Bull Assoc Anat (Nancy). 1978 Mar;62(176):113-22.
The intimal layer of the synovial membrane (SM) includes essentially 2 cell types: A-cells with macrophagic functions and B-cells generally assimilated to fibroblasts. A comparative study of the B-cells in some mammals revealed that these cells possess specific polypeptidergic secretory features which are particularly clear in the mouse. The B-cells, which are more numerous than A-cells and often entirely line the synovial cavity, probably play an essential role in the metabolism of the SM. A study of the development of the SM in the mouse shows that the primitive cleft is formed before any differenciation of the synovial mesenchyme through degradation of the fine mesenchymal layer in direct contact with the chondrogenic layers. The differenciation of the SM coincides with the clarification and dilatation of the synovial cavity. As soon as the SM organizes into intimal and sub-intimal layers (6 days of life), the 2 intimal cell types can be identified by their macrophagic (A-cells) and secretory (B-cells) features. The B-cells, however, only show an appreciable content of typical secretory vesciles at 13 days. Our ultrastructural observations suggest that the B-cells are the source of some specific proteins of the synovial fluid and that they participate in the maintenance of the peculiar structure of the intimal interstitial tissue.
滑膜（SM）的内膜层主要包括两种细胞类型：具有巨噬细胞功能的A细胞和通常被认为与成纤维细胞相似的B细胞。对一些哺乳动物的B细胞进行的比较研究表明，这些细胞具有特定的多肽能分泌特征，在小鼠中尤为明显。B细胞比A细胞数量更多，并且常常完全排列在滑膜腔的内壁，可能在滑膜的代谢中起重要作用。对小鼠滑膜发育的研究表明，原始裂隙在滑膜间充质发生任何分化之前就已形成，这是通过与软骨形成层直接接触的精细间充质层的降解实现的。滑膜的分化与滑膜腔的清晰化和扩张同时发生。一旦滑膜组织成内膜层和内膜下层（出生后6天），这两种内膜细胞类型就可以通过其巨噬细胞（A细胞）和分泌（B细胞）特征来识别。然而，B细胞仅在13天时才显示出明显数量的典型分泌小泡。我们的超微结构观察表明，B细胞是滑液中一些特定蛋白质的来源，并且它们参与维持内膜间质组织的特殊结构。
