Tanaka T, Morioka T, Ayasaka N, Iijima T, Kondo T
First Department of Oral Anatomy, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
J Dent Res. 1990 Mar;69(3):883-9. doi: 10.1177/00220345900690031101.
Microperoxidase (MP, a peptide tracer) was intravenously injected into rats after six days of tooth movement by the Waldo method. Bone resorption was seen along the distal bone surface of the inter-radicular septum of the upper first molar, and tooth root resorption occurred along the mesial and distal surfaces of the distal root of the same molar. Odontoclasts were smaller in size and numbers than osteoclasts, but had the same organelles [multiple nuclei, ruffled borders (RB), clear zones, vacuoles, mitochondria, and specific granules] as osteoclasts. MP was deposited on the resorbed area through the clear zone and was transported into the vacuoles along the channels of the RB. The uptake of MP by odontoclasts was small, compared with that by osteoclasts. Collagen fibrils were found in the channels of the RB but were not detected in the vacuoles. Instead, filament-like structures were seen in the vacuoles and were located very near the collagen fibrils in the channels. Fibroblasts outside the resorbed lacunae had endocytosed collagen. In contrast, some cells close to odontoclasts (osteoclasts) in the dentin (bone)-resorbed lacunae had not endocytosed any collagen fibrils. These findings suggest (1) that odontoclasts resorb the dentin or cementum just as osteoclasts do in bone resorption, (2) that the resorbed area connects with the extracellular spaces of the odontoclasts or osteoclasts, and (3) that the organic components (e.g., collagen fibrils) of dentin or cementum are endocytosed through the channels of the RB in the same manner as that for MP. However, the endocytotic ability of odontoclasts appears inferior to that of osteoclasts.
在采用瓦尔道方法使大鼠牙齿移动6天后，将微过氧化物酶（MP，一种肽示踪剂）静脉注射到大鼠体内。在上颌第一磨牙根间间隔的远中骨表面可见骨吸收，并且在同一磨牙远中根的近中和远中表面发生牙根吸收。破牙细胞的大小和数量比破骨细胞小，但具有与破骨细胞相同的细胞器[多核、皱褶缘（RB）、亮区、液泡、线粒体和特异性颗粒]。MP通过亮区沉积在吸收区域，并沿着RB的通道转运到液泡中。与破骨细胞相比，破牙细胞对MP的摄取量较小。在RB的通道中发现了胶原纤维，但在液泡中未检测到。相反，在液泡中可见丝状结构，且位于通道中胶原纤维的非常近的位置。吸收腔隙外的成纤维细胞已内吞胶原。相比之下，牙本质（骨）吸收腔隙中一些靠近破牙细胞（破骨细胞）的细胞未内吞任何胶原纤维。这些发现表明：（1）破牙细胞与破骨细胞在骨吸收中一样吸收牙本质或牙骨质；（2）吸收区域与破牙细胞或破骨细胞的细胞外空间相连；（3）牙本质或牙骨质的有机成分（如胶原纤维）通过RB的通道以内吞MP的相同方式被内吞。然而，破牙细胞的内吞能力似乎低于破骨细胞。
