Moule A J, Young W G, Adkins K F
Department of Dentistry, University of Queensland, Brisbane, Australia.
J Oral Pathol Med. 1993 Apr;22(4):159-67. doi: 10.1111/j.1600-0714.1993.tb01050.x.
Administration of actinomycin D at a dose level of 0.375 microgram/g resulted in the selective disruption of developing odontoblasts at a critical stage of morphogenesis. A dentin niche was formed which was later repaired by cellular reparative dentin. The cellular changes which resulted in dentin niche formation were studied histologically and ultrastructurally in serial longitudinal and transverse sections from tissues obtained 10 h to 80 h following injection of the drug. Five stages were identified: initial destruction (10-20 h), rapid destruction (30-40 h), debris removal (50-60 h), proliferation (60-80 h) and matrix deposition (post 80 h). The cellular changes found in the dental papilla were considerably different from those found in inflammation, resolution and repair of fibrous connective tissue. These early stages were dominated by apoptosis and heterophagy, and after 80 h by disordered dentin matrix formation. The three-dimensional morphology of the defect was reconstructed from serial sections. The shape of the niche was the result of interference by actinomycin D in the patterns of proliferation and migration of the cells in the apical region of the rat incisor tooth.
以0.375微克/克的剂量水平给予放线菌素D，导致在形态发生的关键阶段发育中的成牙本质细胞被选择性破坏。形成了一个牙本质龛，随后由细胞性修复性牙本质修复。在注射药物后10小时至80小时获得的组织的连续纵向和横向切片中，对导致牙本质龛形成的细胞变化进行了组织学和超微结构研究。确定了五个阶段：初始破坏（10 - 20小时）、快速破坏（30 - 40小时）、碎片清除（50 - 60小时）、增殖（60 - 80小时）和基质沉积（80小时后）。在牙乳头中发现的细胞变化与在纤维结缔组织的炎症、消退和修复中发现的细胞变化有很大不同。这些早期阶段以凋亡和异噬为主，80小时后以无序的牙本质基质形成为主。从连续切片重建了缺损的三维形态。牙龛的形状是放线菌素D干扰大鼠切牙顶端区域细胞增殖和迁移模式的结果。
