| Project/Area Number |
62570702
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | Osaka University |
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Principal Investigator |
YAGI Masaharu (1988) Instructor, Department of Anesthesiology Osaka University Faculty of Medicine, 医学部, 助手 (10210220)
太城 力良 (1987) 大阪大学, 医学部, 助教授 (20107048)
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| Co-Investigator(Kenkyū-buntansha) |
OMORI Masaaki Professor, Department of Psychology Osaka University College of Medical Technolo, 医療技術短期大学部, 教授 (20027965)
富 勝治 大阪大学, 医学部, 助手 (10144487)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Anesthetics / Subanesthetic Concentration / Analgesia / MAC / 吸入麻酔薬 / 精神行動 / 疼痛闘値 / 麻酔作用機序 / 笑気 / 耐性 |
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| Research Abstract |
We assessed the analgesic and anesthetic effects induced subanesthetic concentration of inhalational anesthetics in six healthy volunteers. Analgesic effect was measured as the change in pain threshold using animproved radiant heat algometer. Anesthetic effect was assessed as theprolongation in response time to random auditory stimuli. In the first study, six inhalationl anesthetics eqivalent to 0.2MAC (methoxyflurane, halothane, isoflurane, enflurane, sevoflurane, nitrous oxide) were administered to the subjects. The pain threshold was significantly elevated with nitrous oxide and slightly with methoxyflurane. The pain threshold with other anesthetics was not different from control. The reponse time was significantly, not uniformly prolonged with all the anesthetics. These results suggest that the analgesic property of inhalational anesthetics poorly contributes to anesthetic depth as measured by MAC which is determined by painful stimuli. The second study was aimed to determine;1) the changes of the analgesic and anesthetic actions of nitrous oxide under subanesthetic inhalation(30%), and 2) the possible antagonism of naloxone in these actions. Six volunteers were treated with or without intravenous administration of 1.4mg naloxone. Both anesthetic and analgesic effects did not change during 100 min inhalation or administration of naloxone. These results indicate that the acute tolerance to these actions of nitrous oxide will not occur, and that naloxone will not show a significant antagonstic asctions which can be observed aganist morphine. Analgesic action remained 30 min after nitrous oxide inhalation, while auditory response time returned control values. Analgesic action of nitrous oxide was thought to be affected by some biochemical mechanism.
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