| Project/Area Number |
61570739
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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 |
MASHIMO Takashi Assistant professor, Department of Anesthesiology Osaka University Medical School, 医学部, 講師 (60157188)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIYA Ikuto Professor, Department of Anesthesiology Osaka University Medical School, 医学部, 教授 (80028505)
SUZUKI Keizo Professor, Department of Chemistry Ritsumeikan University, 理工学部, 名誉教授 (40066478)
TASHIRO Chikara Associate Professor, Department of Anesthesiology Osaka University Medical Schoo, 医学部, 助教授 (20107048)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Anesthetics inhalation / enflurane / halothane / methoxyflurane / Membrane protein / Bacteriorhodopsin / Theories of anesthesia / 圧拮抗 / 麻酔の圧拮抗 |
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| Research Abstract |
To understand the molecular mechanism of general anesthesia, we investigated the effect of inhalation anesthetics on the intrinsic membrane protein, bacteriorhodopsin.
1) The effects of inhalation anesthetics on the structure of bacteriorhodopsin in the purple membrane were examined by measurements of the absorption spectrum and the visible circular dichroism (CD) spectrum and assay of the retinal composition. Anesthetics reversibly decreased the absorption at 560 nm but increased that at 480 nm. Anesthetics also reversively diminished the CD spectrum, and increased the ratio of all-trans- to 13-cis-retinal.
2) The effects of inhalation anesthetics on the function of bacteriorhodopsin reconstituted in the soybean phospholipid vesicle were examined by measurement of the light-induced proton translocation. Anesthetics inhibited the proton pump activity of bacteriorhodopsin in a dose-dependent manner.
3) The pressure reversal of anesthetic-induced structural change in the bacteriorhodopsin molecule was examined by spectroscopic measurements using a high-pressure optical cell. High hydrostatic pressure (150, 300 atm) recovered the decrease of absorption at 560 nm. This result demonstrates the pressure-reversal of anesthetic-induced structural change in the protein molecule.
In conclusion, inhalation anesthetics reversibly change the structure and function of bactriorhodopsin, and the anesthetic-induced structural changes are in good correlation with the functional inhibition. Hydrostatic pressure reverses the anesthetic-induced structural change of bacteriorhodopsin.
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