Isozymic Changes in Human Cardiac Myosins Due to Overload

  • Yoshio Yazaki
  • Hidetsugu Tsuchimochi
  • Masahiko Kurabayashi
  • Issei Komuro


During the process of enlargement of the heart due to overload, a significant reconstitution of the organ including myoctes and intracellular constituents occurs, as well as cellular hypertrophy induced by increased synthesis of cellular components in order to meet an increased demand in work. This adaptational phenomenon can be defined at the molecular level in terms of altered transcription of specific genes.

Cardiac myosin isoforms, through their enzymatic activities, regulate both contractility and energy efficiency for contraction of the muscle. Since analysis of myosin isoforms can provide insight into the process of caridac hypertrophy, we developed monoclonal antibodies specific for two types of cardiac myosin, and characterized these isoforms by an immunofluorescence study. Furthermore, we cloned specific genes encoding the heavy and light chains of these cardiac myosin isoforms from the human cDNA library and demonstrated the regulation of their expression in the overloaded human heart. In this study, we investigated human materials to obtain clinical implications from our observations.


Cardiac Myosin Ventricular Myosin Heavy Chain mRNA Atrial mRNA Myosin Isozyme 
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Copyright information

© Springer-Verlag Tokyo 1989

Authors and Affiliations

  • Yoshio Yazaki
  • Hidetsugu Tsuchimochi
  • Masahiko Kurabayashi
  • Issei Komuro
    • 1
  1. 1.The Third Department of Internal Medicine, The Faculty of MedicineUniversity of TokyoTokyoJapan

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