1992 Fiscal Year Final Research Report Summary
Adaptations to Environmental Pressure: The Effect of Pressure on the Properties and Functions of Model Biomembranes.
| Project/Area Number |
02455015
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | The University of Tokushima |
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Principal Investigator |
KANESHINA Shoji The University of Tokushima, Faculty of Engineering, Professor, 工学部, 教授 (80035617)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUKI Hitoshi The University of Tokushima, Faculty of Engineering, Research Associate, 工学部, 助手 (40229448)
SATAKE Hiromu The University of Tokushima, Center for Cooperative Research, Associate Professo, 地域共同研究センター, 助教授 (10124801)
HORI Hitoshi The University of Tokushima, Faculty of Engineering, Associate Professor, 工学部, 助教授 (90119008)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Liposome / Bilayer / Phase transition / High pressure / Micelle / Ion-selective electrode / Local anesthetics / Mitochondria |
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| Research Abstract |
1. Phospholipid bilayers of dipalmitoylphosphatidylcholine (DPPC) have been used as a model for biomembranes. The temperature-pressure phase diagrams of DPPC multilamellar vesicles were constructed, which included four states, i.e., liquid crystal, ripple gel, lamellar gel and interdigitated gel phases. The interdigitated gel phase was induced by pressure and also by the addition of ethanol. Pressure facilitates, rather than antagonizes, the effect of ethanol on the occurrence of interdigitated gel phase in lipid bilayers.
2. The mitochondrial functions (oxygen consumption and ATP synthesis) were used as a measure of adaptation to biological environment. Potentiometry using ion-selective electrode sensitive to lipid-soluble cations such as tetraphenylphosphonium (TPP) ion as a probe is applicable to the estimation of the membrane potential of mitochondria.
3. Coated wire electrodes sensitive to local anesthetic cations were developed, which showed linear responses with Nernstian slopes over a concentration range of 10^<-5> - 10^<-2> M. These electrodes are available for measurement of the local anesthetic concentration under high pressure and in vivo.
4. Surface tension, density and DSC of mixed surfactant solutions were measured. Miscibility in micelles and the changes of volume, enthalpy and entropy of mixing were discussed thermodynamically.
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