Lobo-da-Cunha A
Laboratory of Cell Biology, Institute of Biomedical Sciences and CIMAR, Oporto University, Portugal.
Tissue Cell. 2000 Feb;32(1):49-57. doi: 10.1054/tice.1999.0082.
Digestive cells are the most abundant cell type in the digestive diverticula of Aplysia depilans. These are tall columnar or club shaped cells, covered with microvilli on their apical surface. A large number of endocytic vesicles containing electron-dense substances can be found in the apical zone, but the presence of many heterolysosomes of large diameter is the main feature of these cells. Glycogen particles and some lipid droplets were also observed. Peroxisomes with a circular or oval profile were common, but crystalline nucleoids were not detected in them, although a dense spot in the matrix was observed in a few cases. These organelles were strongly stained after cytochemical detection of catalase activity. The Golgi stacks are formed by 4 or 5 cisternae, with dilated zones containing electron dense material. Arylsulphatase activity was detected in the Golgi stacks and also in lysosomes. Cells almost entirely occupied by a very large vacuole containing a residual dense mass seem to be digestive cells in advanced stages of maturation. The observation of semithin and ultrathin sections indicates that these very large vacuoles are the result of a fusion among the smaller lysosomes. Some images suggest that the content of these large vacuoles is extruded into the lumen of the digestive diverticula.
消化细胞是去毛海兔消化憩室中最丰富的细胞类型。这些细胞为高柱状或棒状，顶端表面覆盖有微绒毛。在顶端区域可发现大量含有电子致密物质的内吞小泡，但这些细胞的主要特征是存在许多大直径的异溶酶体。还观察到糖原颗粒和一些脂滴。具有圆形或椭圆形轮廓的过氧化物酶体很常见，但在其中未检测到结晶状核仁，不过在少数情况下观察到基质中有一个致密斑点。在对过氧化氢酶活性进行细胞化学检测后，这些细胞器被强烈染色。高尔基体堆叠由4或5个扁平囊组成，其扩张区域含有电子致密物质。在高尔基体堆叠和溶酶体中均检测到芳基硫酸酯酶活性。几乎完全被一个含有残余致密物质的非常大的液泡占据的细胞似乎是处于成熟晚期的消化细胞。半薄切片和超薄切片的观察表明，这些非常大的液泡是较小溶酶体融合的结果。一些图像显示这些大液泡的内容物被挤出到消化憩室的管腔中。
