| Project/Area Number |
05453059
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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 |
機能・物性・材料
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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) |
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)
MATSUKI Hitoshi The University of Tokushima, Faculty of Engineering, Assistant, 工学部, 助手 (40229448)
HORI Hitoshi The University of Tokushima, Faculty of Engineering, Asociate Professor, 工学部, 助教授 (90119008)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1994: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | Lipid bilayr / Micelle / Phase transition / Pressure / Local anesthetic / Ion-selective electrode / Mitochondria / Vesicle |
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| Research Abstract |
1) In order to elucidate the mechanism of pressure-anesthetic antagonism, we studied the effects of pressure and anesthetics on the phase-transition temperatures of dipalmitoyl-phosphatidylcholine (DPPC) bilayr membrane. Temperature of the pretransition, as well as the main transition, was elevated by pressure and depressed by anesthetics added. From the colligative thermodynamic framework, two kinds of differential partition coefficients were determined. The volume change due to the transfer of an anesthetic from the aqueous phase to the liquid crystal phase of DPPC membrane, which was evaluated from the pressure dependence of the partition coefficient for the liquid crystal phase, was 16-20 cm^3mol^<-1> according to the anesthetic.
2) Interfacial adsorption of local anesthetics was studied by surface tension and density measurements. We suggested that the surface activity of local anesthetic is proportional to the facility of partitioning the anesthetic into membranes. The magnitude of surface activity (i.e.surface density) was in accord with the potency of the anesthetic action. The enthalpy change of phase transition from the coagel phase to the micellar solution for local anesthetics was determined directly from the DSC thermograms of anesthetic solutions. The molecular interaction of local anesthetics in membranes was studied thermodynamically.
3) Binding of a local anesthetic dibucaine to dimyristoylphosphatidylcholine (DMPC) bilayr membranes was studied by means of an ion-selective electrode sensitive dibucaine cation. DMPC membranes undergo the thermotropic pretransition from the lamellar gel to the ripple gel phase in addition to the main transition from ripple get to the liquid crystal phase. Each of the three stanes exhibits a different receptivity to dibucaine partitioning.
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