© 2001 by European Society of Cardiology
Copyright © 2001, European Society of Cardiology
A growth of ideas: Role of calcium as activator of cardiac contraction
Cardiology Division, Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA
arnold.m.katz@dartmouth.edu
* Address for correspondence: 1592 New Boston Road, P.O. Box 1048, Norwich, VT 05055-1048, USA. Tel.: +1-802-649-3947; fax: +1-802-649-1746
Received 11 June 2001; accepted 13 June 2001
| The first 150 words of the full text of this article appear below. |
| 1. Introduction |
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A role for calcium as activator of cardiac contraction was first suggested in 1883, when Ringer observed that hearts placed in a calcium-free solution ceased to beat [1]. This was an accidental discovery that occurred when Ringers technician used distilled water, rather than the water supplied by the New River Water Company, in studies of isolated frog hearts. Ringer analyzed the pipe water, and found that it contained minute traces of various inorganic substances. When he tested the ability of different salts to support cardiac contraction, Ringer not only identified the ability of calcium to restore cardiac contraction, but also found that this effect was antagonized by potassium [2]. As described below, the negative inotropic effect of potassium was to confuse investigators more than a half century later.
It took almost 80 years before the major systems responsible for the activating effect of calcium on the heart came
| 2. Role of calcium in the activation of muscle contraction |
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| 3. Interactions of calcium with the contractile proteins |
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3.1 Pitfalls in studying the interactions of calcium with actomyosin
3.2 Role of tropomyosin in regulating actin–myosin interactions
3.3 The discovery of troponin
| 4. Calcium removal from the cytosol: role of the sarcoplasmic reticulum |
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| 5. Cardiac plasma membrane calcium channels |
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| 6. Conclusions |
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