open access

https://doi.org/10.14943/doctoral.k11260

https://hdl.handle.net/2115/56228

アスコルビン酸合成能欠如(ODS)ラットの骨組織石灰化における組織学的解析

英語

2014-03-25

Hokkaido University

21, fig5

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization : while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from the semineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

2014-03-25

甲第11260号

博士(歯学)

(主査) 教授 網塚 憲生, 教授 鈴木 邦明, 教授 土門 卓文

歯学研究科（口腔医学専攻）

博士論文

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