Sasaki T, Higashi S, Tachikawa T, Yoshiki S
Acta Anat (Basel). 1983;116(1):74-83. doi: 10.1159/000145728.
Thin sections of newborn rat incisors were examined by tracer experiments and freeze-fracture replication in order to clarify the morphology and permeability of ameloblast junctional complexes in the maturation stage. Ameloblast junctional complexes consisted of gaps and tight junctions at the proximal and distal ends. Whereas the proximal junctional complexes sealed extracellular spaces incompletely, the distal ones formed complete, belt-like barriers around the cell. Tight junctions of these junctional complexes, however, were composed of both continuous and discontinuous rows of particles with various spaces among them. Intravenously injected horseradish peroxidase (HRP) reached the enamel surface through the extracellular spaces among ameloblasts and was absorbed by ameloblasts of the ruffled borders. Pinocytosis and transcellular migration of HRP could not be demonstrated in maturing ameloblasts except in the ruffled border zone.
为了阐明成熟阶段成釉细胞连接复合体的形态和通透性，通过示踪实验和冷冻断裂复型技术对新生大鼠切牙的薄片进行了检查。成釉细胞连接复合体在近端和远端由间隙和紧密连接组成。近端连接复合体不完全封闭细胞外间隙，而远端连接复合体在细胞周围形成完整的带状屏障。然而，这些连接复合体的紧密连接由连续和不连续的颗粒排组成，它们之间有各种间隙。静脉注射的辣根过氧化物酶（HRP）通过成釉细胞之间的细胞外间隙到达釉质表面，并被有褶缘的成釉细胞吸收。除了有褶缘区外，在成熟的成釉细胞中未发现HRP的胞饮作用和跨细胞迁移。
