| Project/Area Number |
15590526
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Hygiene
|
|---|
| Research Institution | Hyogo College of Medicine |
|---|
Principal Investigator |
WADA Yasuhiko Hyogo College of Medicine, Faculty of Medicine, Associate Professor, 医学部, 助教授 (10261653)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IGUCHI Hiroshi Hyogo College of Medicine, Faculty of Medicine, Professor, 医学部, 教授 (90025643)
NISHIIKE Tamako Otemae College, Assistant professor, 講師 (40309448)
NISHIMURA Yasumitsu Kawasaki Medical School, Faculty of Medicine, Assistant professor, 医学部, 講師 (90360271)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Project Status |
Completed (Fiscal Year 2005)
|
| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
|---|
| Keywords | Energy restriction / Hibernation / Electrocardiogram / Heart rate / Hypothermia / Circadian rhythm / Gene expression / Autonomic nerve / 老化制御 / イオンチャンネル / イオンポンプ / 心筋 / 筋原繊維 |
|---|
| 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 gene expression and physiological properties of the heart of C57Bl/6 male mice using AKITA diet. We analyzed the expression of heart mRNA from ER (200 kJ/week) or control (Ct) (400 kJ/week) B6 7-month-old male mice using cDNA microarray covering 6400 genes. mRNAs of 67 genes were increased and those of 153 genes were decreased by ER. It is suggested that the micro-structure and electro-physiological properties of the ER heart may change to adapt low energy and low temperature.
Ambulatory long-term recording of body temperature and electrocardiogram of aged mice revealed that the heart rate of ER mice changed up and down before body temperature did (i.e. hysteresis was observed). It means that the ER heart has an important role in changing body temperature. When body temperature decreased, the heart rate was dramatically decreased to one fifth and supra-ventricular arrhythmia was observed in ER mice, as in hibernators. ER did not change shapes of ECG waves. Analysis of heart rate variability revealed that parasympathetic activity was higher in ER than Ct mice. As aged, circadian rhythm of ER mice became obscure as Ct mice.
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 that anti-arhythmic adaptation may occur in the heart of ER mice, which may contribute to the prolongation of their life span.
|
