| Project/Area Number |
17500297
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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 |
Biomedical engineering/Biological material science
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| Research Institution | Hokkaido University |
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Principal Investigator |
NAIKI Takeru Hokkaido Univ., Grad. School of Info. Sci. and Tech., Asso. Prof., 大学院情報科学研究科, 助教授 (40241385)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAHARA Koichi Hokkaido Univ., Grad. School of Info. Sci. and Tech., Prof., 大学院情報科学研究科, 教授 (20125397)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2005: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Biomechanics / Heart failure / energetics / Cardiac hypertrophy / Cardiomyocyte / Cellular skeleton / Microtubules / SHR / エナジェティクス / 細胞骨格 / 発生張力 / 発生応力 |
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| Research Abstract |
To clarify what mechanisms are involved in the decreased ischemic tolerance of hypertrophied hearts, we studied the effects of cell hypertrophy of myocardial cells on the cell contractility. The left ventricular myocardial cells were isolated from hearts of adult male spontaneously hypertensive rats (SHRs) and from age-matched normal Wistar-Kyoto (WKY) rats with an enzymatic method. Cell contractions induced by electric field stimulation were recorded with a CMOS high-speed camera. A pair of carbon fibers was attached firmly to both ends of a myocardial cell, and the amount of contractile force was determined by analyzing the video images of fiber deflections. The results indicated that no significant difference was observed in the contractile force between hypertrophied cells from SHRs and normal cells from WKY rats. However, the sensitivity of the contractile force to the concentration of either isoproterenol or extracellular Ca^<2+> was significantly different between hypertrophied and normal cells. These results suggest that the energy utilization in hypertrophied myocardial cells is increased when the sympathetic nervous tone is enhanced, and this alteration possibly decreases the ischemic tolerance in hypertrophied hearts.
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