| Project/Area Number |
06670600
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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 |
Respiratory organ internal medicine
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| Research Institution | Tohoku University |
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Principal Investigator |
YANAI Masaru Tohoku Univ., School of Medicine. Assist. professor, 医学部附属病院, 講師 (00210287)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Ameboid movement / Pseudopod formation / Servo-null technique / servo-null technique / pseudopod formation / 細胞内圧 / サーボ・ヌル・テクニック / 細胞遊走 / アメーバ・プロテウス |
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| Research Abstract |
The cortical filament layr of free-living amoebae contains concentrated actomyosin, suggesting that it can contract and produce an internal hydrostatic pressure. We report here on direct and dynamic intracellular pressure (P_<ic>) measurements in Amoeba proteus made using the servo-null technique. In resting apolar A.proteus, P_<ic> increased while the cells remained immobile and at apparently constant volume. P_<ic> then decreased approximately coincident with pseudopod formation. There was a positive correlation between P_<ic> at the onset of movement and the rate of pseudopod formation. These results are the first direct evidence that hydrostatic pressure may be a motive force for cell motion. We postulate that contractile elements in the amoeba's cortical layr contract and increase P_<ic> and that this P_<ic> is utilized to overcome the viscous flow resistance of the intracellular contents during pseudopod formation.
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