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Effects of extracellular environments on development and differenciation of cardiac ion channels

Research Project

Project/Area Number 07407073
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field Circulatory organs internal medicine
Research InstitutionNagoya University

Principal Investigator

TOYAMA Junji  Nagoya Univ.Res.Inst.of Environ.Med., Professor, 環境医学研究所, 教授 (20023658)

Co-Investigator(Kenkyū-buntansha) YAMAZAKI Kiyoko  Seinan Gakuin Univ.Dept.of Literature, Professor, 文学部, 教授 (20192396)
KAMIYA Kaichiro  Nagoya Univ.Res.Inst.of Environ.Med., Assistant, 環境医学研究所, 助手 (50194973)
KODAMA Itsuo  Nagoya Univ.Res.Inst.of Environ.Med., Professor, 環境医学研究所, 教授 (30124720)
YAMAMURA Hideki  Nagoya Univ.Res.Inst.of Environ.Med., Professor, 環境医学研究所, 教授 (40034003)
Project Period (FY) 1995 – 1996
Project Status Completed (Fiscal Year 1996)
Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥2,000,000 (Direct Cost: ¥2,000,000)
Keywordscultured cardiomyocytes / ion channels / growth factor / differentiation / mesoderm / commitment / 中胚葉イオンチャネル / 分化 / コミットメント / 成長因子 / 培養心筋
Research Abstract

This study was aimed to investigate terminal differentiaiotn of cardiac progenitor cells in the early embryogenesis, and ionic currents development after birth in relation to exogenous influence. We heve already established culture systems of the mouse gastrula mesoderm and rat neonatal ventricular myocytes.
Our study in early cardiogenesis indicates that at 7.5 days post coitum, when gastrulation is completed, mesodermal cardiac progenitor cells commit to autonomous differentiation into contractile cardiomyocytes, while 7.25 day post coitum mesoderm requires additional signaling for terminal differentiation. Insulin, insulin-like growth factor and platelet derived growth factor induced cardiomyocytes with spontaneous beating.
In ionic current analysis of neonatal rat ventricular myocytes cultured for 5-15 days, development of ionic currents, especially of I_<to>, showed various patterns, which were dependent on culture states. Hypoxic culture condition retarded or dedifferentiated I_<to> development. Basic fibroblast growth factor enhanced development of I_<to>. Insulin-like growth factor increased the percentage of cells expressing I_<Kur>. In order to explore the molecular mechanism of developmental changes in ionic currents induced by culture condition, we are engaged in microinjection of the exogenous mRNA into cultured cardiomyocytes.
The changes of culture condition, such as hypoxia and modification of culture medium, regulated the ion channels expression. Our findings suggest that environmental factors play important role in ionic channels development as well as in the early cardiogenesis.

Report

(3 results)
  • 1996 Annual Research Report   Final Research Report Summary
  • 1995 Annual Research Report
  • Research Products

    (25 results)

All Other

All Publications (25 results)

  • [Publications] Guo W,Kamiya K,Toyama J: "bFGF promotes functional expressions of transient outward currents in cultured neonatal rat ventricular cells." Eur J Physiol. 430. 1015-1017 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Cheng J Toyama J: "Changes in action potentials and ion currents in long-term cultured neonatal rat ventricular cells." Am J Physiol (Cell Physiol). 271. C93-C102 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Arai A,Yamamoto K,Yamamura H,Toyama J: "Insulin promotes the differentiation of cardiac progenitor cells in the mouse embryos." Environmental Medicine. 40 (In press). (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "Differential effects of chronic membrane depolarization on the K^+ channel activities in cultured rat ventricular cells." Cardiovasc Res. 33. 139-146 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "Evidences of antagonism between amiodarone and triiodothyronine on the K^+ channel activities of cultured rat cardiomyocytes." J Mol Cell Cardiol. 29 (In press). (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kada K,Kamiya K Toyama J: "IGF I regulates the K^+ channel expression of cultured neonatal rat ventricular myocytes." Am J Physiol (Heart Circ Physiol). (In press). (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "bFGF promotes functional expressions of transient outward currents in cultured neonatal rat ventricular cells." Eur J Physiol. 430. 1015-1017 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Cheng J,Toyama J: "Changes in action potentials and ion currents in long-term cultured neonatal rat ventricular cells." Am J Physiol. 271(Cell Physiol 40). C93-C102 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Arai A, Yamamoto K,Yamamura H,Toyama J: "Insulin promotes the differentiation of cardiac progenitor cells in the mouse embryos." Environmental Medicine. 40(in press). (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "Differential effects of chronic membrane depolarization on the K+ channel activities in cultured rat ventricular cells." Cardiovasc Res. 33. 139-146 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "Evidences of antagonism between amiodarone and triiodothyronine on the K+ channel activities of cultured rat cardiomyocytes." J Mol Cell Cardiol. 29(in press). (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kada K,Kamiya K,Toyama J: "IGFI regulates the K+ channel expression of cultured neonatal rat ventricular myocytes." Am J Physiol (Heart Circ Physiol). (in press). (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Guo W,Kamiya K,Toyama J: "bFGF promotes functional expressions of transient outward currents in cultured neonatal rat ventricular cells." Eur J Physiol. 430. 1015-1017 (1995)

    • Related Report
      1996 Annual Research Report
  • [Publications] Guo W,Kamiya K,Cheng J Toyama J: "Changes in action potentials and ion currents in long-term cultured neonatal rat ventricular cells." Am J Physiol (Cell Physiol). 271. C93-C102 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] Arai A,Yamamoto K,Yamamura H Toyama J: "Insulin promotes the differentiation of cardiac progenitor cells in the mouse embryos." Environmental Medicine. 40(In press). (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] Guo W,Kamiya K,Toyama J: "Differential effects of chronic membrane depolarization on th K^+ channel activities in cultured rat ventricular cells." Cardiovasc Res. 33. 139-146 (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] Guo W,Kamiya K,Toyama J: "Evidences of antagonism between amiodarone and triiodothyronine on the K^+ channel activities of cultured rat cardiomyocytes." J Mol Cell Cardiol. 29(In press). (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] Guo W,Kada K,Kamiya K,Toyama J: "IGF I regulates the K^+ channel expression of cultured neonatal rat ventricular myocytes." Am J Physiol(Heart Circ Physiol). (In press). (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] Toyama J,Sugiura H,Kamiya K,Kodama I,Terasawa M and Hidaka H: "Ca2+-calmodulin mediated modulation of the electrical coupling of ventricular myocytes isolated from guinea pig heart." J.Mol.Cell.Cardiol.26. 1007-1015 (1994)

    • Related Report
      1995 Annual Research Report
  • [Publications] Taniguchi A,Toyama J.Kodama I,Anno T,Shirakawa M and Usui S: "Inhomogeneity of cellular activation time and Vmax in normal myocardial tissue under electrical field stimulation." Am.J.Physiol.267. H694-H705 (1994)

    • Related Report
      1995 Annual Research Report
  • [Publications] Watanabe E,Honjo H,Anno T,Boyett MR,Kodama I,Toyama J:"Modulation of pacemaker activity of sinoatrial node cells by electrical load imposed by an atrial cell model." Am J Physiol. 269. H1735-H1742 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] Arai A,Kodama I,Toyama J: "Roles of C1-channels and Ca2+ mobilization in the stretch-induced increase of SA node pacemaker activity." Am J Physiol in press. (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] Ohsugi M,Yamamura H,Semba R and Hideka H: "Immunocytochemical detection of Ca2+-dependent subspoecies ot protein kinase C in mouse embryos before and during compaction." The Histochemical Journal. 26. 641-643 (1994)

    • Related Report
      1995 Annual Research Report
  • [Publications] Kodama I,Suzuki R,Maruyama K,Toyama J: "Electrophysiological effects of SD-3212,a new antiarrhythmic agent with vasodilating action,on guinea pig ventricular cells." Br.J.Pharmacol.114. 503-509 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] Toyama J,Kodama I,Kamiya K,Anno T: "Modes of sodium channel blocking action of class I drugs. In Electropharmacological control of cardiac arrhythmias" Singh BN,Wellens HJJ,Hiraoka M (eds) Futura Publishing Company,Inc.,NY, 746 (1994)

    • Related Report
      1995 Annual Research Report

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Published: 1996-04-01   Modified: 2016-04-21  

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