| Project/Area Number |
16591383
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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 |
Thoracic surgery
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| Research Institution | Akita University |
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Principal Investigator |
YAMAMOTO Hiroshi Akita University, School of Medicine, Associate Professor, 医学部, 助教授 (10270795)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIBASH Kazuyuki Akita University, school of Medicine, Lectuer, 医学部, 講師 (00291617)
NARITA Takuya Akita University, school of Medicine, Assistant Professor, 医学部, 助手 (60396554)
YAMAMOTO Fumio Akita Uniyersity, School of Medicine, Professor, 医学部, 教授 (00127474)
YAMAURA Gembu Akita University, School of Medicine, Assistant Professor, 医学部, 助手 (40375241)
向井田 昌之 秋田大学, 医学部, 助手 (30295977)
千田 佳史 秋田大学, 医学部, 助手 (50400487)
柳 克祥 秋田大学, 医学部, 助手 (50323142)
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| Project Period (FY) |
2004 – 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: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | myocardium / ischemia / reperfusion injury / sodium ion / proton / Na^+ / H^+ exchange / dimethyl amiloride / HCO_3^- cotransporter / Na / H交換機構 / 先天性心疾患 / 細胞成熟度 / イオンチャネル / 細胞内Ca濃度 |
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| Research Abstract |
Objectives : To determine whether or not sodium ion movement during reoxygenation is a determinant of post-ischemic recovery of cardiac function, we examined i) the effect of Na^+/H^+ exchange inhibition during reperfusion or reoxygenation on post-ischemic recovery of cardiac function and ii) the involvement of Na+/HCO_3^-cotransporter in the sodium ion movement.
Methods : Isolated rat hearts were Langendorff-perfused with Krebs-Henseleit bicarbonate buffer and subjected to 20 minutes of normothermic (37C) global ischemia followed by normothermic (37℃) reperfusion. i) 100 μM dimethyl amiloride (DMA) was given during the first 10 min of reperfusion (protocol I) or for 10 minutes after 5-minute hypoxic reperfusion (protocol II). ii) a bicarbonate-free HEPES buffer was used during the first 10 minutes of reperfusion (protocol III). All the protocols were then followed by 25 minutes of noromoxic reperfusion.
Results : i) In protocols I and II, the post-ischemic recovery of left ventricular developed pressure (%LVDP) was significantly greater in the DMA group than in the control group (68.6±5.9 vs. 52.0±6.1%, respectively in protocol Land 66.6±2.8 vs. 52.0±5.5%, respectively in protocol II). In protocol III, there was no difference between the bicarbonate-free group and the control group (35.9±4.9 vs. 24.7±6.7%, respectively).
Conclusions : Sodium ion movement via the Na^+/H^+ exchange during reoxygenation is a determinant of post-ischemic recovery of cardiac function. The Na^+/HCO_3^- cotransporter may not be involved in the sodium ion movement during reperfusion.
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