Anesthetic Receptivity of Lipid Membranes with Different Bilayer Phases
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Accession number;04A0566244
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| Title;Anesthetic Receptivity of Lipid Membranes with Different Bilayer Phases |
| Author;
HATA TAKASHI
(Kochi National Coll. Technol., JPN)
MATSUOKA KAZUHIKO
(Kochi National Coll. Technol., JPN)
ITO KEISUKE
(Kochi National Coll. Technol., JPN)
MATSUKI HITOSHI
(Univ. of Tokushima, Fac. of Eng.)
SATAKE HIROMU
(Univ. of Tokushima)
KANESHINA SHOJI
(Univ. of Tokushima, Fac. of Eng.)
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Journal Title;Hiroshima Journal of Anesthesia
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Journal Code:S0305A
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ISSN:0385-1664
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VOL.39;NO.3/4;PAGE.87-90(2003)
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| Figure&Table&Reference;FIG.3, TBL.1, REF.7 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Partitioning of a local anesthetic dibucaine to ester-linked dipalmitoylphosphdtidylcholine (DPPC) and ether-linked dihexadecylphosphatidylcholine (DHPC) bilayer membranes was studied by using an ion-selective electrode sensitive to dibucaine cation. Lipid bilayer membrane/buffer partition coefficients were directly determined at pH 5.5 as a function of dibucaine concentration and temperature. The limiting partition coefficient extrapolated to infinite dilution was employed because the values of partition coefficients were dependent upon the dibucaine concentration. Bilayer membranes of both lipids undergo thermotropic phase transitions, namely, the pre- and main-transition. Difference in the phase behavior between DPPC and DHPC bilayers lies in the pre-transition. DHPC bilayer membrane undergoes the pre-transition from the interdigitated gel (L.BETA.I) phase to the ripple gel (P.BETA.') phase, in contrast to the pre-transition of DPPC bilayer membrane from the lamellar gel (L.BETA.') phase to the P.BETA.' phase. Each of the states of bilayer membranes exhibited a different receptivity to dibucaine partitioning. The limiting partition coefficients were 3800, 7400 and 36000 for the L.BETA.', P.BETA. and L.ALPHA. phases of DPPC bilayer membrane, and 13000, 7500 and 35500 for the L.BETA.I, P.BETA.' and L.ALPHA. phases of DHPC bilayer membranes, respectively. Partition coefficients into the L.ALPHA. phase are significantly larger than those into the gel (L.BETA.', P.BETA.' and L.BETA.I) phases. The order of partitioning into the gel phases was consistent with that of the surface area occupied by a polar head group of lipid in the bilayer gel phases: L.BETA.'<P.BETA.'<L.BETA.I. (author abst.) |
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