アブストラクト（15巻2号：神奈川歯学）

神奈川歯学

Japanese

Title　： 乳歯根吸収の生化学的研究 - 特に牛歯根膜CytosolのEstrogen結合物質について
Subtitle　： 原著
Authors　： 金子隆男
Authors（kana）　：
Organization　： 神奈川歯科大学口腔生化学教室, 神奈川歯科大学小児歯科学教室
Journal　： 神奈川歯学
Volume　： 15
Number　： 2
Page　： 250-268
Year/Month　： 1980 / 9
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「緒言」 口腔領域における生理的現象として, また, 生物学的, および臨床学的に重要かつ興味ある課題の一つとして歯の交換がある. この現象は, 人を含めた二生歯類にみられる乳歯の脱落と永久歯の萌出という特異な発育的変化である. 山下らによれば, 人で生後4年頃から乳前歯の歯根吸収が始まり, 乳臼歯の脱落から小臼歯の萌出まで, 約7年間にわたって継続するとしている. これらの形態学的研究は種々報告されており, 一條(1975)によれば, 歯根吸収面はcollagen線維の配列のみだれと横紋構造の消失とともに, odontoclastと星状の細胞の出現を特徴とするとし, 大野(1972)はodontoclastのmitochondria, 粗面小胞体, free ribosome, golgi complexは発達したものが多数存在すると報告しているように, 歯根吸収のための細胞分化あるいは細胞機能の変化をうながす機構の存在を示唆している.
Practice　： 歯科学
Keywords　：

English

Title　： Biochemical studies of root resorption of deciduous teeth - On estrogen binding substances in cytosol from bovine periodontal ligament
Subtitle　：
Authors　： TAKAO KANEKO
Authors（kana）　：
Organization　： Department of Oral Biochemistry, Kanagawa Dental College, Department of pedodontics, Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 15
Number　： 2
Page　： 250-268
Year/Month　： 1980 / 9
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： As it has been carried out many clinical and morphological observation concerning physiological root resorption of deciduous tooth, it allows to define in terms of biochemistry, that the phenomena accomplished by the action of certain kinds of metabolic products, such as intermediates of TCA cycle and various kinds of tissue proteases induced from the relative tissue cells at the stage whenever they required. However, it still remains obscure which factors may involve in and to what extent the resorption of deciduous tooth is turned on and off. Since it is reasonable to consider a series of regulators such as physiologically active peptides, vitamins and hormones as for the modulators of cell activities, the author have prefered, one of the steroid hormone as the factor which may be related to the resorpton of deciduous tooth. The steroid hormone used in this experiment is estradiol-17β as the first trial to explore whether the hormone happened to implicate in the mechanisms of root resorption, since the steroid behaves as an effective remodeling modulator for bone regulation. According to the recent advanced knowledge of the molecular biology, the action of steroid on the target cell, the hormone first undergoes an obligatory coupling within the cytoplasm to a specific high affinity receptor molecule and then rapidly accumulates within the nucleus as a functionally active complex bound to chromatin. Then, the complex specially induces the biosynthesis of nucleic acids that are ultimately modified, transported, and thereafter translated in the cytoplasm into biologically active components of the induced new functions. The main efforts of this study, therefore, were attempted to fractionate, purify and try to prove the existence of the molecules, that is called the native form of estrogen receptor, within cell which related in the tissue adjacent to the root resorption of deciduous tooth. Therefore, fresh bovine mandible during period of mixed dentition were obtained from the slaughterhouse, and the periodontal ligament was dissected from deciduous teeth which had been absorbed already 1/3, 1/2 and 2/3 of the root and also the other related tissues such as the periodontal ligament and pulp from primary and permanent teeth were collected respectively. After thorough washing extracellular, fluid from the tissues, cytosol prepared according to the procedures of homogenization and ultrasonication were fractionated by means of sucrose gradient centrifugation, gel filtration with Sepharose 6B and heparin-agarose affinity chromatografy. Although the chromatographic evidences revealed the facts that cytosol from the periodontal ligament and pulp of deciduous and parmanent teeth possesed more than four macromolecules which were capable of binding to [3H]-estradiol-17β, there were distinguished differences in molecular distribution among these tissues. Moreover, it was clearly demonstrted that the native forms of estrogen receptor were progressively increased in their amounts and moleculer distribution according to the stage of root resorption. Addition to the findings mentioned above, as it was determined that the amino acids composition were completely different each other between the stage of 1/3 and 2/3 root resorption, therefore, it was possible to elucidate that the induced proteins in the cell at those stage due to the different [3H]-estradiol receptors may exhibit an independent characteristics in their physiological performances.
Practice　： Dentistry
Keywords　：