Characteristics and Functional Implications of Spontaneous Sarcoplasmic Reticulum-Generated Cytosolic Calcium Oscillations in Myocardial Tissue
The process by which electrical excitation of cardiac muscle cells leads to contraction is incompletely understood. It is clear, however, that in all mammalian hearts, release of Ca2+ from the sarcoplasmic reticulum (SR) contributes to the activation of the myofilaments. Spontaneous SR oscillatory Ca2+ release (Fig. 1), given the required conditions, appears to be a universal phenomenon in mammalian preparations (see Lakattaet al., 1985 for review). While spontaneous chaotic cellular contractions, a mechanical sequalae of SR Ca2+ oscillations (CaOsc), was observed over 70 years ago (see Capogrossiet al., 1986b), the universality of CaOsc had not generally been recognized, and its multiple effects on myocardial function have not generally been considered collectively.
KeywordsSarcoplasmic Reticulum Spontaneous Release Cardiac Preparation Normal Membrane Potential Mammalian Cardiac Muscle
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