Prostak K, Skobe Z
J Craniofac Genet Dev Biol. 1985;5(1):75-88.
Secretory granule ultrastructure of teleost inner dental epithelial (IDE) cells has been reported to be similar to procollagen granules of other cells synthesizing collagen. This study describes the ultrastructure of secretory products in odontogenic cells during enameloid matrix formation in cichlids after inhibition of granule secretion with colchicine. Thirty-six fish were injected with 0.1 mg colchicine, then three were killed first at 2-hr intervals for 12 hr, then daily for 5 days. Tooth buds were processed for transmission electron microscopy, and ultrastructural alterations were assessed for each post-injection interval. Four hours post-injection, IDE cells contained increased numbers of secretory granules, lightly stained granules, dilated cisternae of the granular endoplasmic reticulum, and intercellular amorphous material. After 6 hr, the IDE intercellular amorphous material additionally contained electron dense deposits, and after 8 hr, the intercellular material had fibers similar in appearance to enameloid collagen. No ultrastructural changes were detected in odontoblasts that were in close proximity to the enameloid matrix. Only odontoblasts synthesizing predentin were affected by colchicine, and the observed alterations were similar to those seen in IDE cells. It is concluded that IDE cells synthesize and secrete ectodermal enameloid matrix collagen.
据报道，硬骨鱼内牙上皮（IDE）细胞的分泌颗粒超微结构与其他合成胶原蛋白的细胞的前胶原颗粒相似。本研究描述了在用秋水仙碱抑制颗粒分泌后，丽鱼科鱼类釉基质形成过程中牙源性细胞分泌产物的超微结构。给36条鱼注射0.1毫克秋水仙碱，然后在12小时内每隔2小时处死3条鱼，之后每天处死3条鱼，持续5天。将牙胚进行透射电子显微镜处理，并对注射后每个时间间隔的超微结构变化进行评估。注射后4小时，IDE细胞内的分泌颗粒数量增加，颗粒染色浅，颗粒内质网池扩张，细胞间出现无定形物质。6小时后，IDE细胞间无定形物质中额外出现电子致密沉积物，8小时后，细胞间物质中有外观与釉基质胶原蛋白相似的纤维。在靠近釉基质的成牙本质细胞中未检测到超微结构变化。只有合成前期牙本质的成牙本质细胞受秋水仙碱影响，观察到的变化与IDE细胞中的变化相似。结论是，IDE细胞合成并分泌外胚层釉基质胶原蛋白。
