アブストラクト（34巻1号：神奈川歯学）

神奈川歯学

Japanese

Title　： 初代培養骨芽細胞におけるin vitro石灰化と脂質に関する研究
Subtitle　： 原著
Authors　： 松原聡, 高橋常男*, 内村登, 高橋和人*
Authors（kana）　：
Organization　： 神奈川歯科大学小児歯科学教室, *神奈川歯科大学口腔解剖学教室
Journal　： 神奈川歯学
Volume　： 34
Number　： 1
Page　： 61-74
Year/Month　： 1999 / 3
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「緒言」 石灰化機構を形態学的に観察すると, 未分化間葉系細胞から分化した骨芽細胞は石灰化に向けて, 第一段階では骨芽細胞の細胞膜中ALPase活性が高まり, コラーゲン性タンパク質および非コラーゲン性タンパク質の分泌と, 同時に酸性のリン脂質(Phospholipids:以下PL)を主体とする基質小胞(Matrix Vesicle:以下MV)を分泌する. 第二段階として, MV内でリン酸とカルシウムが濃縮されアパタイト結晶に成長し, 最終的にそれら結晶は膜外に放出され, コラーゲン細線維および細線維間に結晶核形成が波及していく. 生化学的検索では, ウシ, トリの骨端軟骨の各細胞層中の脂質は極性脂質であるリン脂質と糖脂質, および非極性脂質である遊離コレステロールなどに分類され, 石灰化の進行に伴い, また石灰化層に近づくにつれて各脂質量が増加することが明らかにされている. さらに, 分離されたMVには強い酸性リン脂質, 特にカルシウム親和性の高いホスファチジルセリン, リゾリン脂質や遊離コレステロールなどが含有されていることが報告されている.
Practice　： 歯科学
Keywords　： 脂肪酸, 石灰化, グルコース, 骨芽細胞

English

Title　： In vitro Study on the Lipids Associated Mineralization in Primary Cultured Osteoblasts
Subtitle　：
Authors　： Satoshi MATSUBARA, Tsuneo TAKAHASHI*, Noboru Uchimura, Kazuto Takahashi*
Authors（kana）　：
Organization　： Department of Pediatric Dentistry, Kanagawa Dental College, *Department of Oral Anatomy, Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 34
Number　： 1
Page　： 61-74
Year/Month　： 1999 / 3
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： [Abstract] It is known that some of the glucose taken into the cytoplasm cells, such as hepatocytes and adipocytes, is converted to fatty acids (FA) and triacylglycerol (TG). The present investigation was undertaken to morphologically and biochemically verify the influence of glucose and FA on the process of mineralization in cultures of rat calvaria derived osteoblast-like cells. The cells were incubated under three different glucose concentrations (2.8, 5.6 and 25 mM) in the medium. Glucose at the highest concentration tested affected the cytodifferentiation of osteoblast-like cells and increased alkaline phosphatase activity ; it also increased the size and number of areas of extracellular insoluble calcium phosphate assessed by alizarin red staining. The observed effect was dependent on glucose concentration. When fixed with a mixed prefixative of glutaraldehyde and tannic acid adjusted at pH 7.3, lipidic structures within the cells showed a lamellar phase, electron densely stained multilamellar structure, indicating the presence of fatty acid-soaps. In contrast to this, when fixed with a mixed prefixative of glutaraldehyde and malachite green at pH 6.8, the structures observed at pH 7.3 showed an oil base, wholly electron opaque droplets, in parts sometimes with multilamelar structures at the periphery of the droplet, suggesting that morphological characteristics of the structure observed may fit well with that of free fatty acid (FFA) regarding with pH-dependency. There was a marked increase in size and number of more lipid droplets in the cytoplasm of the cells. Biochemical study on the FFA, TG and phospholipids (PL) with the Zaph method and thin layer chromatography showed that FFA and TG contents of the cultures were increased by glucose in a concentration-dependent fashion, whereas PL content was unaffected. Hence, these morphological and biochemical findings indicate that the FFA may be closely associated with mineralization process in present culture system. It is also consistent with the view that osteoblasts can synthesize FA from glucose ; the produced FA may be utilized to trap extracellular calcium for bone mineralization.
Practice　： Dentistry
Keywords　：