• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Mechanisms of ventricular arrhythmias during myocardial ishemia and reperfusion

Research Project

Project/Area Number 61480206
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field Circulatory organs internal medicine
Research InstitutionDepartment of Circulation and Respiration, The Research Institute of Environmental Medicine, Nagoya, University

Principal Investigator

TOYAMA Junji  Professor, The Research Intitute of Environmental Medicine, 環境医学研究所, 教授 (20023658)

Co-Investigator(Kenkyū-buntansha) KODAMA Itsuo  Assistant Professor, The Resaech Institute of Environmental Medicine, 環境医学研究所, 助教授 (30124720)
坪井 直哉  名古屋大学, 環境医学研究所, 助手 (20183486)
Project Period (FY) 1986 – 1987
Project Status Completed (Fiscal Year 1987)
Budget Amount *help
¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥3,500,000 (Direct Cost: ¥3,500,000)
KeywordsHypoxia-reperfusion / Single ventricular myocytes / Sarcomere Shortening / Oscillatory membrane potential / 膜電位振動 / 細胞内Ca^<2+>-overload / 再灌流不整脈 / 単一心筋細胞 / サルコメア縞 / 画像処理 / 好気的代謝阻害 / triggered activity / 細胞内【Ca^(2+)】overload
Research Abstract

Electrical and mechanical activities of guinea pig single ventricular myocytes were investigated under conditions simulating hypoxiareoxygenation. The localized movement of sarcomere was recorded simultaneously with membrane potential, and analyzed using a microcomputerbased image processing system. Exposure to 5 mM CN^- caused progressive shortening of action potential duration and attenuation of twitch contraction. The myocytes became inexcitable about 30 to 70 min after the CN^- treatment. On removal of CN^-, the myocytes exhibited periodic miniature membrane depolarizations from the resting potential level of -95 mV. The miniature depolarizations increased in frequency and in amplitude within 2-5 min and, in some cases, spontaneous action potentials were induced. When depolarizations were smaller than 5 mV in amplitude and longer than 500 msec in duration, they were accompanied by localized sarcomere shortening like a propagating contractile wave (unifocal oscillation). Membrane depolarizations of larger amplitude and shorter duration were associated with a more uniform pattern of localized sarcomere shortening (multifocal ocsillation). Such electrical and mechanical oscillations were attenuated gradually and disappeared within 6-8 min. Trains of electrical stimuli applied during the washing out period caused transient augmentation of potential fluctuation and enhancement of synchronization of sarcomere shortening. These results suggest that nonuniform elevation of intracellular calcium concentration at the resumption of oxidative phosphorylation may initiate oscillatory fluctuations of membrane potential leading to abnormal spontaneous excitation.

Report

(2 results)
  • 1987 Final Research Report Summary
  • 1986 Annual Research Report
  • Research Products

    (15 results)

All Other

All Publications (15 results)

  • [Publications] 本荘晴朗: 医用電子と生体工学. 28. 231 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] Haruo Honjo: Environmental Medicine. 31. 81-86 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] 本荘晴朗: 名古屋大学環境医学研究年報. 38. 96-99 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] Haruo Honjo: J. Moll. Cell. Cardiol.20(Suppl. 1). S41 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] Haruo Honjo: Jpn. Circ. Res.51. 794 (1987)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] H,Honjo et al.: "Fluctuation of membrane potential in isolated single ventricular myocytes of guinea pig at a resumption of oxidative phosphorylation." J. Mol. Cell. Cardiol.20(Suppl:1). 41 (1988)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] H,Honjo et al.: "Electrical and mechanical oscillations of guinea pig single ventricular myocytes after transient inhibition of oxidative phosphorylation." Environmental Medicine. 31. 81-86 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] H,Honjo et al.: "Electrical and mechanical oscillation of guinea pig single ventricular myocytes after the transient inhibition of oxidative phosphorylation." Jpn. Circ. J.51. 794 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] H,Honjo et al.: "Electrical and mechanical oscillation of guinea pig single ventricular myocytes after the transient cessation of oxidative phosphorylation." Ann. of The Res. Inst. of Environmental Medicine. (in Japanese). 38. 96-99 (1987)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1987 Final Research Report Summary
  • [Publications] 佐藤俊雄: 環境医学研究所年報. 37. 251-254 (1986)

    • Related Report
      1986 Annual Research Report
  • [Publications] Toshio Sato: Environmental Medicine. 30. 77-82 (1986)

    • Related Report
      1986 Annual Research Report
  • [Publications] Toshifumi Watanabe: Environmental Medicine. 30. 97-103 (1986)

    • Related Report
      1986 Annual Research Report
  • [Publications] Haruo Honjo: J.Mol.Cell Cardiol.19Suppl.I. S35 (1987)

    • Related Report
      1986 Annual Research Report
  • [Publications] Toshio Sato: IEEE.

    • Related Report
      1986 Annual Research Report
  • [Publications] Toshio Sato: 医用電子と生体工学. 24特別号. 134 (1986)

    • Related Report
      1986 Annual Research Report

URL: 

Published: 1987-03-31   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi