日本沼虾中肠腺细胞的超微结构研究

应用电镜技术研究了日本沼虾中肠腺细胞的类型及超微结构。结果表明：日本沼虾中肠腺上皮细胞大多呈柱状，顶端具有微绒毛，依结构和功能不同可分为Ｒ细胞、Ｆ细胞、Ｂ细胞和Ｅ细胞４种类型。Ｒ细胞具有吸收、贮存营养物质的功能，细胞内含有脂滴、糖原和吞噬咆，内质网、线粒体等细胞器数量少；Ｆ细胞内蛋白酶原合成活动旺盛，粗面内质网极为发达，在数量上比Ｒ细胞多，几乎充满整个细胞；Ｂ细胞微绒毛较短，以胞饮方式吸收营养，在

Ultrastructural studies on the cells of midgut gland in the Macrobrachium nipponense

The ultrastrutures of different type cells of the midgut gland in the freshwater prawn, Macrobrachium nipponense, were studied through electronic microscopy.The columnar epithlium which lines the ducts of the midgut gland consists of four type cells (E,R,F,B) similar to that described in other decpaoda. The apical surface of all type cells has numeros microvilli. R-cells,which fuctions in food absorption and food storage, are characterized by lipid droplet, glycogen and phagosoma filled with debris. F-cells are tall columnar epithelial cells with abundant mitochondria and rough endoplasmic reticulum by which the digestive enzymes are apparently synthesized. However, no secretive activities are observed in F-cells. The microvilli of B-cells are shorter than that of other cells.B-cells can pinocytose material from the tobule lumen of the gland. A large number of vacuoles were found in B-cells. The vacuoles filled with myelin figures are concemed with intracellular digestion.Rupture and release of the B-cells vacuole contents directly into the lumen are regarded as aprocess of holocrine secretion.E-cells are polyhedral,undifferentated and show a high ratio of nuclear to cytoplasm. The cytoplasm contains relatively sparse rough endoplasmic reticulum and small mitochondria.