| Project/Area Number |
61480102
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | National Cardiovascular Cenler Research lnstitute, |
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Principal Investigator |
SUGA Hiroyuki National Cardiovascular Center Research Institute, Director, 循環動態機能部, 部長 (90014117)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Nobuaki National Cardiovascular Center Research Institute, Director, 循環動態機能部, 研究員 (50197456)
FUTAKI Shiho National Cardiovascular Center Research Institute, Director, 循環動態機能部, 研究員 (60190112)
NOZAWA Takashi National Cardiovascular Center Research Institute, Director, 循環動態機能部, 研究員 (00180737)
YASUMURA Yoshio National Cardiovascular Center Research Institute, Director, 循環動態機能部, 研究員 (30183669)
後藤 葉一 国立循環器病センター研究所, 循環動態機能部・冠循環研究室, 室員 (40142179)
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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 |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | heart / myocardium / energy efficiency / syslolic pressure-volume area / mechanical energy / oxygen consumplion / 心筋 / エナジェティクス / 効率 / 圧容積図 / ATP |
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| Research Abstract |
The aim of this project was to search for factors which can increase the energy conversion efficiency of the contractile machinery of myocardium. We used excised, cross-circulated dog left ventricles and analyzed the relationship belween left ventricular oxygen consumption (V02) and systolic pressure-volume area (PVA) as a measure of the total mechanical energy of ventricular contraction. The slope of the V05-PVA relation which is virtually linear indicales the reciprocal of the overall efficiency of the contractile machinery. We studied this efficiency 1) under cooling myocardium from 37C to 29C, 2) under global ischemia by lowering coronary perfusion pressure from 80 to 50 and to 30 mmhg, and 3) in quick release contractions in which release time was varied during systole. We found virtually no change in the slope of the V02-PVA relation under cooling and ischemia. However, quick release decreased the slope, suggesting an increased efficiency. However, We interpreted this result to reflect that the maintenance of PVA is energy-dependent and abbreviation of the maintenance saved V02. All these results help us better understand the coupling between mechanics and energetics of myocardium.
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