Byrne Maria
Department of Biology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada.
J Morphol. 1986 May;188(2):179-189. doi: 10.1002/jmor.1051880205.
The ultrastructure of the morula cells of Eupentacta quinquesemita and the distribution of these cells in the dermal connective tissue are described. Morula cells are abundant in the dermis and appear to function in the maintenance of the extracellular matrix (ECM) as a source of ground substance material. The synthetic activity of these cells is described in detail. Morula cells are filled with large secretory vesicles containing three electrondense materials which are derived from rough endoplasmic reticulum and Golgi activity. The synthetic product of these cells contains glycosaminoglycans and is secreted into the ECM by degranulation. The ultrastructural and histochemical similarity of the degranulation product to the ECM ground substance suggests that they are comprised of the same material. Morula cells appear to function primarily in connective tissues where ground substance predominates. The cells often contain secretory vesicles at various stages of formation, all of which eventually mature and degranulate. The synthetic pathway of the morula cells appears to result ultimately in the complete disruption and death of the cells. The function of morula cells in the holothuroid ECM is discussed, and the synthetic activity of the cells is compared with that of other secretory cells.
描述了五触手海参桑氏海参桑氏幼虫细胞的超微结构以及这些细胞在真皮结缔组织中的分布。桑氏幼虫细胞在真皮中丰富，似乎作为基质物质的来源在维持细胞外基质（ECM）中发挥作用。详细描述了这些细胞的合成活性。桑氏幼虫细胞充满了含有三种电子致密物质的大分泌囊泡，这些物质来源于粗面内质网和高尔基体的活动。这些细胞的合成产物含有糖胺聚糖，并通过脱颗粒分泌到细胞外基质中。脱颗粒产物与细胞外基质基质在超微结构和组织化学上的相似性表明它们由相同的物质组成。桑氏幼虫细胞似乎主要在基质占主导的结缔组织中发挥作用。这些细胞通常含有处于不同形成阶段的分泌囊泡，所有这些囊泡最终都会成熟并脱颗粒。桑氏幼虫细胞的合成途径似乎最终导致细胞的完全破坏和死亡。讨论了桑氏幼虫细胞在海参细胞外基质中的功能，并将这些细胞的合成活性与其他分泌细胞的合成活性进行了比较。
