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[Ca2+-dependent phosphorylation and ATPase activity of cardiac muscle myosin in experimental myocardial infarction]

M D Printsev, N Iu Frolova, E P Ivanteeva

    Voprosy Meditsinskoi Khimii
    |January 1, 1984
    PubMed

    Insights

    Myosin ATPase activity and calcium-dependent phosphorylation decreased in canine myocardial ischemia. These changes in myosin function are crucial for understanding acute myocardial infarction pathogenesis.

    Area of Science:

    • Biochemistry
    • Cardiovascular Physiology
    • Molecular Biology

    Context:

    • Myocardial infarction leads to ischemic conditions affecting cardiac muscle function.
    • Myosin, a key contractile protein, plays a critical role in heart muscle contraction.
    • Alterations in myosin's enzymatic and regulatory properties are implicated in heart disease.

    Purpose:

    • To investigate the changes in myosin ATPase activity and phosphorylation in the ischemic myocardium.
    • To elucidate the role of myosin alterations in the pathogenesis of acute myocardial infarction.

    Summary:

    • Experimental infarction in dogs resulted in decreased myosin ATPase activity in the ischemic myocardium within 24 hours.
    • A decrease in the intensity of Ca2+-dependent phosphorylation of myosin was observed.
    • Concurrently, an increased rate of phosphorylation was noted in the myosin light chain (18,000 molecular mass).

    Impact:

    • These findings highlight significant alterations in myocardial myosin's biochemical properties during acute ischemia.
    • Understanding these changes in ATPase activity and phosphorylation is vital for studying the pathogenetic mechanisms of contractile dysfunction in myocardial ischemia.

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