von Zglinicki T, Roomans G M
Department of Human Anatomy, University of Uppsala, Sweden.
Scanning Microsc. 1989 Jun;3(2):483-90; discussion 490-3.
Subcellular ion distribution in villus, crypt, Paneth and smooth muscle cells of the mouse small intestine under resting conditions was investigated by X-ray microanalysis of ultrathin cryosections. In addition, the mass distribution was estimated by measuring the optical transmission of the compartments in transmission electron micrographs. Each cell type is characterized by a special composition in terms of the major monovalent ions Na, K, and Cl. In particular, among crypt epithelial cells, those cells containing small secretion granula (termed crypt A cells) also display cytoplasmic ion concentrations significantly different from crypt epithelial cells lacking secretion granula (crypt B cells). Monovalent ion concentrations in the cytoplasm of Paneth cells, muscle cells, and crypt epithelial cells lacking secretion granula are higher than expected from osmotic considerations. Hence, significant binding of ions to cytoplasmic polyelectrolytes is assumed in these cells. There are gradients of dry mass and K concentration from the luminal to the basal side of the cell, both in crypt and in villus cells. The terminal web in these cells is rich in Na and Cl. The elemental composition of the large, dark secretion granula in Paneth cells is similar to that of the small dark granula in crypt cells. However, the two morphologically different types of granula within the Paneth cells have a significantly different elemental composition, which might reflect maturation of secretion granula.
通过对超薄冷冻切片进行X射线微分析，研究了静息状态下小鼠小肠绒毛、隐窝、潘氏细胞和平滑肌细胞中的亚细胞离子分布。此外，通过测量透射电子显微镜图像中各区域的光学透射率来估计质量分布。每种细胞类型在主要单价离子钠、钾和氯方面都具有特殊的组成。特别是，在隐窝上皮细胞中，那些含有小分泌颗粒的细胞（称为隐窝A细胞）的细胞质离子浓度也与缺乏分泌颗粒的隐窝上皮细胞（隐窝B细胞）显著不同。潘氏细胞、肌肉细胞和缺乏分泌颗粒的隐窝上皮细胞细胞质中的单价离子浓度高于渗透压考虑所预期的浓度。因此，假定这些细胞中离子与细胞质多聚电解质有显著结合。在隐窝和绒毛细胞中，从细胞腔侧到基底侧存在干质量和钾浓度梯度。这些细胞中的终末网富含钠和氯。潘氏细胞中大型深色分泌颗粒的元素组成与隐窝细胞中小型深色颗粒的元素组成相似。然而，潘氏细胞内两种形态不同的颗粒类型具有显著不同的元素组成，这可能反映了分泌颗粒的成熟过程。
