アブストラクト（29巻4号：神奈川歯学）

神奈川歯学

Japanese

Title　： 骨形成過程の骨芽細胞にみられる多層膜構造物の電顕的研究
Subtitle　： 原著
Authors　： 永井宏人, 正木久秀, 高橋常男, 高橋和人
Authors（kana）　：
Organization　： 神奈川歯科大学口腔解剖学教室
Journal　： 神奈川歯学
Volume　： 29
Number　： 4
Page　： 333-354
Year/Month　： 1995 / 3
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「緒言」 当教室では, 骨芽細胞の成熟分化を考慮し, 石灰化と脂質との関連性について形態学的観点から検索を行っている. その検索過程で, 頭頂骨片を用いたin vitro実験では, パラサイロイドホルモン, プロスタグランディンE2またはビタミンD3などの投与実験により, 骨片から遊出してくるマクロファージ群, および骨芽細胞様細胞群の細胞の形態的特徴, また同様培養条件下での石灰化現象の特徴など興味ある所見を報告してきた. これらの報告の中で, 還元性固定剤であるグルタールアルデヒドとタンパク質の沈殿作用を有するタンニン酸を併用することで, 切超薄片上において高い電子密度をもつ多層膜構造物multilamellar structures(MLS)が観察されることを写真掲載したものの, これらの構造について十分な言及は行わなかった. 従って, 本研究はグルタールアルデヒド・タンニン酸混合固定法で可視された多層膜構造物の実体について詳細な検討を加えたものである.
Practice　： 歯科学
Keywords　： 骨芽細胞, 石灰化, タンニン酸, 多層膜構造, 脂質, 培養

English

Title　： An Electron Microscopic Study of Multilamellar Structures Associated with Osteoblasts in a Mineralization Process
Subtitle　： Original article
Authors　： Hirohito NAGAI, Hisahide MASAKI, Tsuneo TAKAHASHI, Kazuto Takahashi
Authors（kana）　：
Organization　： Department of Oral Anatomy, Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 29
Number　： 4
Page　： 333-354
Year/Month　： 1995 / 3
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： Abstract : The purpose of this study is to elucidate a morphological relationship between lipids and mineralization. As a first morphological approach, an ultrastructural examination on multilamellar structures (MLS) associated with osteoblasts was undertaken. Parietal bone fragments from new born mice (in vivo study) and mice of late gestation period (in vitro study) were dissected. For in vitro study, the fragments were cultured in α-MEM for approximately 10 days. Specimens from both in vivo and in vitro studies were immediately prefixed with either 2.5% glutaraldehyde only (G), or a mixed solution of 2.5% glutaraldehyde・0.2% tannic acid (GTA) or 0.1% ruthenium red (GRR), followed by either 1% osmium tetroxide only (O) or 1.5% potassium ferrocyanide reduced 1% osmium tetroxide postfixation (FO). A mixed solution of G・O was also tried. A special attention was paid on final pH value of each fixative using 0.1M cacodylate buffer solution. The ultrastructure of the osteoblasts was investigated, focusing especially on the appearance of concentric lamellar structures. These MLS seemed to be lipid-rich materials which were resistant to extraction and translocation during tissue processing by GTA prefixation, and were recognized a high frequency. The TA was considered to affect the appearance of tightly packed, more osmiophilic lamellar structures. The MLS was stained electron densely by RR just like TA, suggesting the presence of acidic mucopolysaccharide. The periphery of the MLS seemed to be an acid-resistant. Morphological characteristics composed of alternating dark and light layers (approximately 6nm) in MLS of osteoblast were quite similar to that of the in vitro study, and the same as "so called lamellar bodies" in lung tissue. Two types of MLS were observed ; 1) the intracellular MLS being continuous to the Golgi complex and the endoplasmic reticulum and 2) the extracellular MLS being continuous to the plasma membrane. The fact that these MLS are continuous to the existing membrane component might suggest that the MLS constituent arises from the membrane, or similar membrane components. The true cytological function of these MLS remains unclear, and more detailed examination including a biochemical viewpoint will be also necessary.
Practice　： Dentistry
Keywords　：