| Project/Area Number |
63480348
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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 |
麻酔学
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| Research Institution | Tottori University |
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Principal Investigator |
HIJI Yasutake (Tottori Univ.), Professor, 医学部, 教授 (90094101)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIKAWA Osamu (Dept, of Physiol.), Res. Assoc., 医学部, 助手 (20108799)
IMOTO Toshiaki (Sch. of mod.), Asst. Prof., 医学部, 助教授 (10109639)
井元 敏明 鳥取大学, 医学部, 助教授 (70037331)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥5,500,000 (Direct Cost: ¥5,500,000)
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| Keywords | Local Anesthesia / Anesthetic Enhancement / Mmocarboxylate / Procaine / Adsorption Model / Hydrogen Clearance Test / Tissue Blood Flow / 局所麻酔 / モノカルボン酸イオン / サリチル酸ナトリウム / 坐骨神経 / 紫外吸収 / 臨界吸着比 / ザリガニ巨大神経 / 吸着率 / 脱着率 |
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| Research Abstract |
Measurements of action potentials recorded from giant nerve fibers of the crayfish abdomen showed that by addition of an organic acid salt to a local anesthetic solution, The onset of anesthetic action became more rapid and the duration of action was prolonged. Similar results were also obtained in rat vagalnerves. The chemical structure of compounds having these enhancing effects was a monocarboxylic anion with a benzene ring or an aliphatic hydrocarbon. Topical application of anesthetic solutions to the skin of flexor side of the forearm in humans revealed that the duration of anestehsia evaluated by the apparent decrease of the number of pain points was significantly prolonged by the addition of salicylate. The use of local anesthetics combined with organic acid salts would be promising in clinical practice to enhance their action greatly.
To investigate the mechanism of this enesthetic cnhancement, the action of procaine was considered on the basis of a simple Langmuir-type adsorption model. Rate constants in the model were estimated by observing the time course of procaine desorption from the nerve using the UV light absorption techhnique. The model suggested the following two points. 1. The anesthetic enhancement by some organic anions could be explained by the acceleration of procaine adsorption and lowering the critical adsorption ratio. 2. The maximum adsorption of procaine observed was about 40 umol per 1 g wet weight of the nerve, the value of which corresponded to 1 : 1 adsorption of procaine to phospholipids in the membrane.
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