| Project/Area Number |
12670314
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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 |
Hygiene
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| Research Institution | Hyogo College of Medicine (2001-2002)
Akita University (2000) |
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Principal Investigator |
WADA Yasuhiko Hyogo College of Medicine, Dept.of Medicine, Associate Professor, 医学部, 助教授 (10261653)
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| Co-Investigator(Kenkyū-buntansha) |
KOIZUMI Akio Kyoto University Graduate School of Medicine, Professor, 大学院・医学研究科, 教授 (50124574)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | Energy restriction / Heart / Gene expression / cDNA array / Hypothermia / Daily torpor / 24-hour EGG / Arrhythmia / 心筋 / 心拍リズム / 老化制御 / 筋原繊維 / 寒冷耐性 / 熱ショックタンパク / 心筋細胞 / 耐寒性 |
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| Research Abstract |
Energy restriction (ER) without malnutrition has been known to retard aging processes and extend the life span in various species of mammals. We investigated the effects of ER on morphological and physiological properties of the heart of C57B1/6 male mice using AKITA diet. We analyzed the expression of heart mRNA from ER (200 kJ/week) or control (400 kJ/week) B6 11-month-old male mice using cDNA array membranes including 588 genes. mRNAs increased by ER were fetal myosin alkali light chain genes and transcriptional factor 1 for heat shock gene (HSF1). Electron microscopy revealed that ER cardiac muscle had very few lipid droplets, which were often found in control one. Heart of ER mice was not hypertrophic compared to control. Ambulatory long-term recording of body temperature and electrocardiogram of aged mice revealed that the heart rate of ER mice changed before body temperature did, and the rate was dramatically decreased to one fifth when body temperature was decreased. When body temperature changed up and down dangerous arrhythmia, such as ventricular premature beat, was not found in ER mice. These findings mean that the heart of ER mice has good adaptation to hypothermia. Moreover, it is suggested that the ER heart has an important role in changing body temperature.
In conclusion, ER may alter structure and functional properties of the heart and make it adaptable to wide range of body temperature and energy availability. This also suggests possibility of ER as a means of preventing lethal arrhythmia, and also sudden deaths, among the elder.
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