Laurie G W, Leblond C P
J Histochem Cytochem. 1982 Oct;30(10):973-82. doi: 10.1177/30.10.6290565.
The parietal layer of the rat yolk sac includes a 5 microliter thick sheet known as Reichert's membrane that exhibits properties of basement membranes. Its inner side is lined by a single layer of loosely distributed cells referred to as endodermal cells. Both Reichert's membrane and endodermal cells were examined at 13-14 days' gestation with emphasis on the ultrastructure of the Golgi apparatus, the identification of its component parts by specific phosphatase activities, and its possible role in the cells' secretory process. Reichert's membrane is composed of a series of stacked layers similar to basal laminae and composed of a network of fibrils with a diameter of 2-8 nm along which dots are located at irregular intervals. The endodermal cells contain the usual organelles, including interconnected rough endoplasmic reticulum (rER) cisternae and a prominent Golgi apparatus. With the help of phosphatase reactions, the stacks of Golgi saccules were divided into a) "phosphatase-free" saccules, the first ones on the cis or forming side, b) one or two "intermediate" saccules in the middle of the stacks, containing nicotinamide adenine dinucleotide phosphatase activity, c) one or two "last" saccules rich in thiamine pyrophosphatase activity on the trans or mature side, and d) continuing beyond the trans side, the GERL element displaying acid phosphatase activity. The latter is associated with profiles equally rich in acid phosphatase and tentatively considered to be prosecretory granules. Finally, the ectoplasm adjacent to Reichert's membrane displays large, acid phosphatase-containing structures tentatively considered to be secretory granules. Thus, the extensive rER network, the well-compartmentalized Golgi apparatus, and the presence of structures which may be prosecretory and secretory granules indicate that the endodermal cells are well-equipped for the secretion of the components of Reichert's membrane.
大鼠卵黄囊的壁层包含一层5微升厚的薄片，即赖歇特膜，它具有基底膜的特性。其内侧衬有单层松散分布的细胞，称为内胚层细胞。在妊娠13 - 14天时对赖歇特膜和内胚层细胞进行了检查，重点是高尔基体的超微结构、通过特定磷酸酶活性鉴定其组成部分以及它在细胞分泌过程中的可能作用。赖歇特膜由一系列类似于基膜的堆叠层组成，由直径为2 - 8纳米的纤维网络构成，沿这些纤维不规则间隔分布着小点。内胚层细胞含有常见的细胞器，包括相互连接的粗面内质网（rER）池和一个突出的高尔基体。借助磷酸酶反应，高尔基体囊泡堆叠被分为：a）“无磷酸酶”囊泡，位于顺面或形成面的第一层；b）堆叠中间的一两个“中间”囊泡，含有烟酰胺腺嘌呤二核苷酸磷酸酶活性；c）在反面或成熟面富含硫胺素焦磷酸酶活性的一两个“最后”囊泡；d）在反面之外继续延伸的，显示酸性磷酸酶活性的GERL元件。后者与同样富含酸性磷酸酶的轮廓相关，暂被认为是前分泌颗粒。最后，与赖歇特膜相邻的外质显示出大的、含有酸性磷酸酶的结构，暂被认为是分泌颗粒。因此，广泛的rER网络、高度分隔的高尔基体以及可能是前分泌和分泌颗粒的结构的存在表明内胚层细胞具备分泌赖歇特膜成分的良好条件。
