ROLE OF AGING ON PRECONDITIONING AND INTRACELLULAR CA2+ DYNAMICS IN THE ISOLATED RAT HEART.
| Project/Area Number |
14571425
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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 |
Anesthesiology/Resuscitation studies
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| Research Institution | University of Yamanashi (2003-2004)
山梨医科大学 (2002) |
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Principal Investigator |
YAMAGUCHI Toshiaki University of Yamanashi, Department of Research Interdisciplinary Graduate School of Medicine and Engineering, Research Associate, 大学院・医学工学総合研究部, 助手 (80242650)
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| Co-Investigator(Kenkyū-buntansha) |
OGUCHI Takeshi University of Yamanashi Hospital, Lecturer, 医学部附属病院, 講師 (60201399)
KUMAZAWA Teruo University of Yamanashi Hospital, Professor, 医学部附属病院, 教授 (10092404)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | MYOCARDIAL FUNCTION / AGING / ISOLATED HEART / ISCHEMIC HEART / FURA-2 / PRECONDITIONING / ANESTHETICS / CALCIUM |
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| Research Abstract |
We have hypothesized that aging reduces the efficacies of anesthetic preconditioning (Experiment 1) and ischemic preconditioning (Experiment 2) in the ischemic isolated rat hearts.
Hearts were excised from young (6 weeks), adult (9 weeks), and aged (>60 weeks) rats. The hearts were perfused with a Langendorff system. After loading and washout of Fura-2/AM, hearts were randomly assigned to control or isoflurane-preconditioning groups (Experiment 1), and control or ischemic-preconditioning groups (Experiment 2). Isoflurane was administered for 8 min, followed by washout for 5 min. In the ischemic preconditioning groups, hearts were subjected to three ischemia-reperfusion cycle. Afterwards, no-flaw ischemia was induced for 10 min, followed by reperfusion for 20 min.
In the experiment 1, preconditioning with isoflurane reduced the duration of ventricular arrhythmia in young hearts. However, in adult and aged hearts, the preconditioning did not shorten arrhythmia. Preconditioning with isoflur
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ane sgnificantly reduced the increase in diastolic [Ca2+]i only in young hearts. The preconditioning with isoflurane did not depress the increases in total DHBAs (that indicated oxygen free radical production) in all group.
In the experirnent 2, ischemic preconditioning reduced the duration of ventricular arrhythmia in young hearts. However, in aged hearts, the preconditioning did not shorten arrhythmia. Ischemic preconditioning reduced the increase in diastolic [Ca2+]i only in young hearts. The ischemic preconditioning did not depress the increases in total DHBAs in young and aged hearts.
The present data suggest that aging reduces the effectiveness of anesthetic preconditioning in providing cardioprotection against ventricular arrhythmia during reperfusion, which may be associated with myocardial [Ca2+]i dynamics during reperfusion. Aging also reduces the effectiveness of ischemic-preconditioning in providing cardioprotection against ventricular arrhythmia during reperfusion, which may be associated with myocardial [Ca2+]i dynamics during reperfusion. The applications of anesthetic preconditioning and ischemic preconditioning prior to ischemia did not affect hydroxyl radical production. Less
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Report
(4 results)
Research Products
(9 results)
