HUSCAP logo Hokkaido Univ. logo

Hokkaido University Collection of Scholarly and Academic Papers >
Theses >
博士 (歯学) >


Files in This Item:
Takeshi_Miyamoto.pdf1 MBPDFView/Open
Please use this identifier to cite or link to this item:
Related Items in HUSCAP:

Title: ラット脳各種ATPase活性に対する静脈麻酔薬の作用
Other Titles: Effects of intravenous anesthetics on the activities of various ATPases in rat brain
Authors: 宮本, 健志 Browse this author
Keywords: 静脈麻酔薬
V型 ATPase
Basal Mg2+ -ATPase
Issue Date: 25-Mar-2014
Abstract: The effects of general anesthetics on functional proteins remain to be clarified. This study examined whether the activity of magnesium-dependent ATPase (Mg2+ -ATPase) in the rat brain is a target for intravenous anesthetics. The effects of propofol, pentobarbital, and thiopental on magnesium-dependent ATPase in the plasma membrane fraction (PII) and microsomal fraction (PIII) isolated from rat brain homogenates by the method of Pottorf were examined. The optimal pH values for Mg2+ -ATPase activities in PII and PIII were 9.4 and 7.4, respectively. The Mg2+ -ATPase activity of PII was inhibited by about 80% by NaN3(sodium azide), an inhibitor of F-type ATPase. The Mg2+ -ATPase activity of PIII was inhibited by about 30% by the V-type ATPase inhibitor bafilomycin, and by about 10% by the P-type ATPase inhibitor vanadate. Western blotting analysis revealed that the largest amount of F-type ATPase was detected in PII, and the largest amount of V-type ATPase was detected in PIII. We defined all ATPase activity that was insensitive to the above inhibitors as basal Mg2+ -ATPase activity. In the presence of these inhibitors, we examined the effects of intravenous anesthetics on the activities of various ATPases. Propofol inhibits V-type ATPase activity, PII basal Mg2+ -ATPase activity, and PIII basal Mg2+ -ATPase activity in a dose-dependent manner; however, F-type ATPase activity was uniquely stimulated by about 80% by propofol at concentrations below 0.6 mM. Pentobarbital inhibited all types of ATPases in a dose-dependent manner. Thiopental inhibited all types of ATPases to varying degrees.
静脈麻酔薬の各種ATPaseに対する作用の報告は多いが,作用機構の詳細については未だ不明な点が多い.ATPaseにはP型ATPase,V型ATPase,F型ATPaseなどが存在し,活性発現にMg2+(Mg)を必要とするが,役割や性質の不明なMg-ATPaseは多数報告されている.本研究ではラット脳に存在するMg-ATPaseを分析するとともに,静脈麻酔薬の作用を検討した.ラット全脳から,Pottorfの方法に従って,形質膜(PII)とミクロソーム(PIII)分画を得た.Mg-ATPase活性の至適pHはPIIが約9.4,PIIIは約7.4であった.PIIのMg-ATPase活性はF型ATPaseの阻害剤であるNaN3によって約80%抑制され,PIIIのMg-ATPase活性はP型ATPase及びV型ATPaseの阻害剤であるNa3VO4及びBafilomycine A1によってそれぞれ約10%及び30%抑制された.ウエスタンブロッティングの結果からも、F型ATPaseはPIIに,V型ATPaseはPIIIに最も多く検出された.上記阻害剤で抑制されないMg-ATPase活性をBasal Mg-ATPaseとし,各阻害剤の存在下で各ATPaseを分別して静脈麻酔薬の影響を調べた.PropofolはV型ATPase活性、PII及びPIII Basal Mg-ATPase活性を濃度依存的に抑制したが,F型ATPase活性は80%程度活性化した.PentobarbitalはすべてのATPase活性を濃度依存的に抑制した.ThiopentalもすべてのATPase活性を抑制したが,その程度は各ATPaseによって異なった.以上の結果から、静脈麻酔薬はラット脳Mg-ATPase活性を基本的に抑制するが,Propofolはミトコンドリアに特異的な作用を及ぼすことが示唆された.
Conffering University: 北海道大学
Degree Report Number: 甲第11272号
Degree Level: 博士
Degree Discipline: 歯学
Examination Committee Members: (主査) 教授 藤澤 俊明, 教授 鈴木 邦明, 教授 舩橋 誠
Degree Affiliation: 歯学研究科(口腔医学専攻)
Type: theses (doctoral)
Appears in Collections:学位論文 (Theses) > 博士 (歯学)
課程博士 (Doctorate by way of Advanced Course) > 歯学院(Graduate School of Dental Medicine)

Export metadata:

OAI-PMH ( junii2 , jpcoar_1.0 )

MathJax is now OFF:


 - Hokkaido University