ビオチン欠乏がラット海馬に及ぼす影響 (平成17年麻布大学公的研究助成金事業研究成果報告)  [in Japanese] Effects of biotin deficiency on rat hippocampuses  [in Japanese]

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Author(s)

Abstract

本研究は,ビオチン欠乏がラット海馬へ及ぼす影響について,Timm染色法を用いて海馬組織を組織計測するとともに,DNAマイクロアレイ法を用いて海馬組織における遺伝子発現を検証した。組織学的観察では,歯状回,CA1,CA3の各エリアにおいてBD群の方がBS群より神経細胞が小さい傾向を示し,ビオチン欠乏により海馬神経細胞の代謝活性が低下していることが示唆された。また,Hilus,Lucidum領域のシナプス密度は,背側海馬(頭側)では両群の間に差は認められなかったが,腹側海馬(尾側)ではBD群の方がBS群より有意に増加しており,ヒト側頭葉てんかんに見られる所見に類似することが示唆された。さらに海馬組織の遺伝子発現については,BD群では細胞間や細胞内情報伝達に関わる複数の遺伝子(アセチルコリン作動性受容体,AMPA型受容体,神経軸策伸張に関わる関連遺伝子)が抑制されており,ビオチンが遺伝子発現にも重要な働きを示すものと推察された。ビオチンは脳機能の維持,特に記憶・学習に関与している可能性がある。

Biotin participates in gluconeogenesis, amino acid metabolism, as well as fatty acid synthesis. In former studies, we observed that long-term potentiation in the biotin-deficient rat hippocampus was inhibited and the rats' maze-learning ability deteriorated. This study examined how biotin deficiency effects the rat hippocampus using Timm's staining and DNA microarray. Wistar rats were used in this study. They were fed biotin deficient diet. Experimental (BD) group was given a vehicle and control (BS) group was given biotin (200μg/ml/kg, i.p.) by daily. Four weeks later, the rats were euthanized and their hippocampuses were removed. Six hippocampuses from each group were embedded in paraffin and were stained with HE and Timm's method to measure the neuronal cell number and synapse density of the hippocampuses. The remaining two hippocampuses were used to examine gene expression using analysis of DNA microarray. In histological observation, the cells in the dentate gyros, CA1, and CA3 regions of the BD group were smaller than the BS group. The synapse density of ventral hippocampuses (caudal) of the BD group was significantly higher than the BS group. Also, expression of multiple intercellular signaling related genes, such as acetylcholinergic receptors, AMPA-type receptors, and nerve axon elongation related genes, was inhibited in the BD group. It is likely that biotin participates in maintaining brain functioning, especially in memory and learning functions.

Journal

  • Journal of Azabu University

    Journal of Azabu University 13・14, 125-127, 2006

    Azabu University

Codes

  • NII Article ID (NAID)
    110006391499
  • NII NACSIS-CAT ID (NCID)
    AA11561468
  • Text Lang
    JPN
  • Article Type
    特集
  • Journal Type
    大学紀要
  • ISSN
    13465880
  • NDL Article ID
    8884340
  • NDL Source Classification
    ZM2(科学技術--科学技術一般--大学・研究所・学会紀要)
  • NDL Call No.
    Z74-C608
  • Data Source
    NDL  NII-ELS 
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