Ultrastructural features of odontoclasts that resorb enamel in human deciduous teeth prior to shedding
Ultrastructural features of odontoclasts that resorb enamel in human deciduous teeth prior to shedding
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脱落前吸收人类乳牙牙釉质的破牙细胞的超微结构特征
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Kazuo Suzuki
中科院分区：
文献类型：
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作者：
N. Sahara;Y. Ashizawa;Koyo Nakamura;T. Deguchi;Kazuo Suzuki
三种牙齿硬组织，即，牙骨质、牙本质和釉质被称为“破牙本质细胞”的多核细胞再吸收。这些细胞具有与骨吸收破骨细胞相似的形态和功能特征。然而，关于牙釉质吸收，这是一个过程，可能会发生在牙齿萌出，令人满意的超微结构数据碎牙吸收仍然缺乏。应用光镜、透射电镜和扫描电镜观察了人乳牙脱落前破牙细胞吸收釉质的超微结构和组织化学特征。吸收釉质的破牙细胞是抗酒石酸酸性磷酸酶（TRAP）阳性的多核巨细胞，与吸收牙本质和牙骨质的细胞基本相同。超微结构上，它们的细胞质中有大量的线粒体、溶酶体和游离的多聚核糖体。此外，他们的特点是丰富的大细胞质空泡含有釉质晶体的细胞质相对的皱褶边缘。虽然它们在釉质表面延伸出一个发育良好的皱褶边界，但在这些细胞中很少看到一个清晰的区域-一个通常没有细胞器的区域。在许多情况下，细胞通过其细胞质的外周部分与釉质表面非常紧密地接触。与未吸收的完整釉质相比，吸收表面的釉质棱柱含有更松散的电子透明釉质晶体。此外，在皱褶边缘的细胞外通道和细胞质中各种大小的细胞质液泡中发现了许多从釉基质中释放出来的细针状或板状釉晶体。釉质基质的表层发生破牙吸收，甲苯胺蓝和TRAP活性染色呈阳性。本研究的结果表明，破牙细胞再吸收釉质分泌酸以及有机成分，包括水解酶，到其皱褶的边界下的再吸收区，他们吞噬已从部分脱矿釉质基质中释放的晶体，酸，随后溶解它们intracellularly。Anat.Rec.252：215-228，1998。© 1998 Wiley利斯公司
Three dental hard tissues, i.e., cementum, dentin, and enamel, are resorbed by multinucleated cells referred to as “odontoclasts.” These cells have morphological and functional characteristics similar to those of bone‐resorbing osteoclasts. However, concerning enamel resorption, which is a process that may occur during tooth eruption, satisfactory ultrastructural data on odontoclastic resorption are still lacking. Ultrastructural and histochemical characteristics of odontoclasts resorbing enamel of human deciduous teeth prior to shedding were examined by means of light microscopy and transmission and scanning electron microscopy. Odontoclasts that that resorbed enamel were tartrate‐resistant acid phosphatase (TRAP)‐positive multinucleated giant cells that were essentially the same as those that resorbed dentin and cementum. Ultrastructurally, they had numerous mitochondria, lysosomes, and free polysomes in their cytoplasm. In addition, they were characteristically rich in large cytoplasmic vacuoles containing enamel crystals in the cytoplasm opposite the ruffled border. Although they extended a well‐developed, ruffled border against enamel surface, a clear zone—an area typically devoid of organelles—was rarely seen in these cells. In many cases, the cells were in very close contact with the enamel surface by the peripheral part of their cytoplasm. The enamel prisms at the resorption surface contained more loosely packed and electron‐lucent enamel crystals compared with those of unresorbed, intact enamel. Furthermore, numerous thin needle‐ or plate‐like enamel crystals that were liberated from the enamel matrix were found in the extracellular channels of the ruffled border and in various‐sized cytoplasmic vacuoles in their cytoplasm. The superficial layer of the enamel matrix undergoing odontoclastic resorption stained positively with toluidine blue and for TRAP activity. The results of the present study suggest that odontoclasts resorbing enamel secrete acids as well as organic components, including hydrolytic enzymes, into the resorption zone underlying their ruffled border and that they phagocytose crystals that have been liberated from the partially demineralized enamel matrix by acids, subsequently dissolving them intracellularly. Anat. Rec. 252:215–228, 1998. © 1998 Wiley‐Liss, Inc.
DOI：
10.1016/s0021-9258(18)98430-9
发表时间：
1993-05
期刊：
The Journal of biological chemistry
影响因子：
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作者：
F. Ross;J. Chappel;Jose I. AlvarezS;Diane Sanderll;W. Butler;M. Farach-Carson;Keith A. Mintz;P. Robey;Steven L. TeitelbaumS;David A. Chereshll
通讯作者：
F. Ross;J. Chappel;Jose I. AlvarezS;Diane Sanderll;W. Butler;M. Farach-Carson;Keith A. Mintz;P. Robey;Steven L. TeitelbaumS;David A. Chereshll
DOI：
10.1016/0045-6039(87)90479-9
发表时间：
1987-09-01
期刊：
CELL DIFFERENTIATION
影响因子：
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作者：
GLOWACKI, J;LIAN, JB
通讯作者：
LIAN, JB