| Project/Area Number |
09670767
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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 |
Circulatory organs internal medicine
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| Research Institution | Kanazawa Medical University |
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Principal Investigator |
IMANISHI Sunao Kanazawa Medical University, Department of Physiology, Professor, 医学部, 教授 (90108689)
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| Co-Investigator(Kenkyū-buntansha) |
KURATA Yasutaka Kanazawa Medical University, Department of Physiology, Assistant Professor, 医学部, 講師 (00267725)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | adrenomedullin / cardiac muscle / E-C coupling / microeleetrade / strain gange / calcinm current / パッチクランプ法 / イオン電流 / 心筋の興奮収縮連関 / ヒト心筋 / 膜イオン電流 |
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| Research Abstract |
Direct effect of adrenomedullin (AM) on myocardial cells is as yet equivocal. In addition, the mechanism underlying the direct action of AM on cardiac muscle reams not clear. We have investigated the direct effect of AM on action potential and contraction of papillary muscle excised from guinea pig right, ventricle. The substances at. Concentration ranging from 10ィイD1-8ィエD1 to 10ィイD1-6ィエD1 M caused a slight prolongation of action potential duration at 20% level of the repolarization and an increase of developed tension. This effect. Was abolished in the presence of L-type CaィイD12+ィエD1 channel blocker, suggesting that the positive inotropic effect produced by AM is due to enhancement of L-type CaィイD12+ィエD1 possibly via activation of intracellular cAMP. However, it is reported that AM showed a negative inotropic effect. On rabbit and ferret cardiac muscle. On the other hand, we found that AM might not, induce any effect on slope of pacemaker potential of action potential in rabbit sinoatrial node cell. Further studies into both direct action and its node on cardiac muscles of various mammalian species including human myocardial cells are necessary.
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