Abstract
Although it is well established that ionic calcium level can regulate myofilament activity, expressed either as ATPase activity or force generation, it is also quite clear that this relation is subject to substantial modification by agents or conditions such as magnesium (1–3) or ionic strength (4–6). Whether shifts in the pCa-myofilament activity curves are due to alterations in the binding of calcium to the myofilament or to some effect on processes beyond the binding of calcium is unknown. Since many of the reactions related to force generation take place after calcium is bound to the myofilament a multitude of possible sites exist for magnesium and/or ionic strength to shift the calcium-myofilament activation relation. Figure 1 provides, in broad terms, a view of these reactions.
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Briggs, N., Shiner, J., Gleason, N., Bruni, F., Solaro, J. (1977). Calcium Binding and Cardiac Myofibril Activation. In: Riecker, G., et al. Myocardial Failure. International Boehringer Mannheim Symposia. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-46352-5_10
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DOI: https://doi.org/10.1007/978-3-642-46352-5_10
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