2000 Fiscal Year Final Research Report Summary
The role of anti-oxidant enzyme in cardioprotective effects of exercise and heat stress
| Project/Area Number |
11470162
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Osaka University |
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Principal Investigator |
KUZUYA Tsunehiko Osaka University Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (80150340)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIDA Masashi Kobe College, Professor, 人間科学部・人間科学科, 教授 (40283783)
MASUYAMA Tohru Osaka University Graduate School of Medicine, Assistant Professor, 医学系研究科, 助手 (70273670)
SATO Hideyuki Osaka University Graduate School of Medicine, Assistant Professor, 医学系研究科, 助手 (70167435)
OTSU Kinya Osaka University Graduate School of Medicine, Assistant Professor, 医学系研究科, 助手 (20294051)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Mn-SOD / TNF / IL / ischemia-reperfusion / oxygen radicals / exercise / Cardioprotective therapy |
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| Research Abstract |
Oxygen radical, which is synthesized during cardiac ischemia-reperfusion, has been found to be a potential mediater for cardiac cell injury. To protect the ischemia-reperfusion injury, some approach to eliminate the production of oxygen radical has been tried. On the basis of the beneficial effects of exercise on the cardioprotection against various stresses including ischemia-reperfusion, we aimed to determine whether exercise induces some anti-oxidant effect in the heart.
(1) Mechanism of Mn-SOD induction by exercise
After rats were trained to exercise in the wheel, trained rats were sacrified and hearts were subjected to the biochemical analysis. Production of super-oxide, measured by using Dichrolofluorescein, was increased. MRNA and protein levels of TNF and IL were also increased. When rats were treated with TNF, IL, or H2O2, Mn-SOD was increased at both mRNA, protein, and activities.
(2) Induction of Mn-SOD in vascular system
On the basis of our result that stress-induced Mn-SOD has beneficial effects on heart, we further examined the Mn-SOD induction of vascular smooth muscle cells in response to ischemia. Ischemic stress also increased Mn-SOD at mRNA and activity. Smooth muscle cells over-expressing Mn-SOD could be resistant to the ischemic stress.
In conclusion, we determined that exercise induces Mn-SOD in virtue of the production of TNF and IL, leading to the anti-oxidant effects on the heart.
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