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1990 Fiscal Year Final Research Report Summary

Experimental Studies on the Occurrence of Cardiac Hypertrophy in Ischemic Heart and Its Possible Mechanisms

Research Project

Project/Area Number 63480224
Research Category

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

Allocation TypeSingle-year Grants
Research Field Circulatory organs internal medicine
Research InstitutionToyama Medical and Pharmaceutical University

Principal Investigator

SASAYAMA Shigetake  Toyama Med. & Pharm. Univ. Professor, 医学部, 教授 (70109007)

Co-Investigator(Kenkyū-buntansha) MIWA Kunihisa  Toyama Med. & Pharm. Univ. Assistant, 医学部, 助手 (70166221)
FUJITA Masatoshi  Toyama Med. & Pharm. Univ. Hospital Assistant Professor, 附属病院, 講師 (50190046)
Project Period (FY) 1988 – 1990
KeywordsCoronary occlusion / Myocardial hypertrophy / Myocardial cell / Ultrasonic dimension gauge / Adrenergic alpha1 receptor / Adrenergic beta receptor / Calcium channel drug binding receptor
Research Abstract

We evaluated whether repeated brief coronary occlusion induces myocardial hypertrophy in the region subjected to reversible ischemic insult. In 5 conscious dogs, a subendocardial segment length in the area perfused by the left circumflex coronary artery (LCCA) was measured along with left ventricular pressure. After complete recovery from surgery, 167 (mean) 2 min LCCA occlusions were repeated for 22 days. The resting end-diastolic segment length in the LCCA area was increased by 6.6% (p<0.05). On histologic examination, there was a disproportionate increase in myocardial cell size in the LCCA area compared with the area perfused by the left anterior descending coronary artery (LAD) (18.2 mu vs. 15.4 mu, p<0.05). In an additional similarly instrumented 5 dogs, myocardial cell size in the LCCA and LAD areas was comparable (14.2mu vs. 14.0mu, p=NS). We conclude that the repeated brief ischemic episodes induced regional myocardial hypertrophy confined to the ischemic area.
The maximal bind … More ing site density (Bmax) for [^3] prazosin binding was 13.0<plus-minus>6.5 (fmol/mg protein) (mean <plus-minus>SD) in the nonischemic area and 14.6<plus-minus>9.5 (fmol/mg protein) in the ischemic area. The dissociation constant (K_D) was 0.17<plus-minus>0.13 (nM) in the nonischemic area and 0.17<plus-minus>0.17 (nM) in the ischemic area. Both the parameters were not significantly different. The Bmax, 72.2<plus-minus>35.5 (fmol/mg protein) and the K_<D'> 1.00<plus-minus>0.25 (nM) for H dihydroalloprenolol binding, in the nonischemic area were not significantly different from those (Bmax : 76.8<plus-minus>25.8 (fmol/mg protein), K_<D:> 1.43<plus-minus>0.75 (nM) in the ischemic area, respectively. The Bmax, 250<plus-minus>126 (fmol/mg protein) and the K_<D'> 0.24<plus-minus>0.03 (nM) for [^3H] (+) PN200-100 binding in the nonischemic area were also insignificantly different from 175<plus-minus>19 (fmol/mg protein) and 0.03<plus-minus>0.14 (nM) in the ischemic area, respectively. These results suggest that the mechanism contributing to myocardial hypertrophy induced by repeated occlusion appears to involve no quantitative and qualitative changes of adrenergic alpha1 and beta, and also calcium channel drug binding receptors. Less

  • Research Products

    (9 results)

All Other

All Publications (9 results)

  • [Publications] Fujita Masatoshi: "Changes in isovolumic segment shortening following acute Coronary occlusion: disproportionate effects of anterior versus posterior ischemia." International Journal of Cardiology. 22. 29-35 (1989)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yamanishi Kazuto: "Importance of myocardial ischaemia for recruitment of coronary collateral circulation in dogs." Cardiovascular Research. 24. 271-277 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Fujita Masatoshi: "Importance of myocardial ischemia for coronary collateral development in conscious dogs." Internationl Journal of Cardiology. 27. 179-186 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yamanishi Kazuto: "Regional myocardial hypertrophy induced by repeated brief coronary occlusion in conscious dogs." American Journal of Cardiovascular Pathology (in press). (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 宮城 裕子: "心筋膜 Dihydropyridine 受容体結合に対するdiltiazem および verapamil の影響。" 薬理と治療. 18(suppl 2). 111-117 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Fujita M, Sasayama S, Araie E, Yamanishi K, Ohno A, McKown DP, Franklin D: "Changes in isovolumic segment shortening following acute coronary occlusion : disproportionate effects of anterior versus posterior ischemia" International Journal of Cardiology. 22 :. 29-35, (1989)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yamanishi K, Fujita M, Ohno A, Sasayama S: "Importance of myocardial ischemia for recruitment of coronary collateral circulation in dogs" Cardiovascular Research. 24(4) :. 271-277, (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Fujita M, Sasayama S, Ohno A, Yamanishi K, Araie E, Franklin D: "Importance of myocardial ischemia for coronary collateral development in conscious dogs" International Journal of Cardiology. 27 :. 179-186, (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yamanishi K, Fujita M, Araie E, Ohno A, Sasayama S, Okada E: "Regional myocardial hypertrophy induced by repeated brief coronary occlusion in conscious dogs" American Journal of Cardiovascular Pathology. (1991)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1993-08-12  

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