| Project/Area Number |
07671658
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | Osaka University |
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Principal Investigator |
MASHIMO Takashi Osaka University Medical School Associate Professor, 医学部, 助教授 (60157188)
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| Co-Investigator(Kenkyū-buntansha) |
YANAGIDA Toshio Osaka University Medical School Professor, 医学部, 教授 (30089883)
NISHIMURA Shinya Osaka University Medical School Assistant Professor, 医学部・付属病院, 助手 (00263286)
YOSHIYA Ikuto Osaka University Medical School Professor, 医学部, 教授 (80028505)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | actomyosin / actin / motility / ATPase / local anesthetic / lidocaine / tetracaine |
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| Research Abstract |
Using a recently developed in vitro motility assay, we have demonstrated that local anesthetics, lidocaine and tetracaine directly inhibit myosin-based movement of single actin filaments in a reversible dose-dependent manner. The inhibitory action of the local anesthetics on actomyosin sliding movement was pH dependent ; the anesthetics were more potent at higher pH values, and this reaction was accompanied by an increased proportion of the uncharged form of the anesthetics. QX-314, a permanently charged derivative of lidocaine, had no effect on actomyosin sliding movement. These results indicate that the uncharged form of local anesthetics is predominatly responsible for the inhibition of actomyosin sliding movement. The local anesthetic inhibited aliding movement but hardly interfered with the binding of actin filaments to myosin on the surface or with actomyosin ATPase activity at low ionic strength. To characterize the actomyosin interaction in the presence of anesthetics, we measured the binding and breaking force of the actomyosin complex. The binding of actin filaments to myosin on the surface was not affected by lidocaine at low ionic strength. The results suggest that the binding and ATPase of actomyosin are governed predominantly by ionic interaction, which is hardly affected by anesthetics ; whereas the force generation requires hydrophobic interaction, which plays a major part of the strong binding and is blocked by anesthetics, in addition to the ionic interaction.
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