Abstract
The relationship between cellular calcium (Ca) stores and isometric contractile force was investigated in isolated, gas-perfused cat hearts. The hearts were preperfused for approximately 5 min with substrate-free Krebs solution modified to contain 0, 1.25, 2.5, 5.0 or 10.0 mEq/liter Ca, gas-perfused for up to 120 min, and then perfused with zero-Ca Krebs solution. Contractile force and [Ca] in the effluent fluid were measured. Our results indicate that: (a) The washout of Ca was characteristic of a three compartment system, (b) A Ca compartment directly associated with muscle contraction was identified by correlation of the rate of Ca washout with the rate of decay of contractility (r = 0.79). (c) Ca content in the compartment was correlated with contractile force (r = 0.77). (d) Contractile force and the Ca content of the compartment which was correlated with contractility approached a steady state during 120 min of gas perfusion.
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Selected References
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- CALDWELL P. C., WALSTER G. STUDIES ON THE MICRO-INJECTION OF VARIOUS SUBSTANCES INTO CRAB MUSCLE FIBRES. J Physiol. 1963 Nov;169:353–372. doi: 10.1113/jphysiol.1963.sp007261. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caldwell P. C. Factors governing movement and distribution of inorganic ions in nerve and muscle. Physiol Rev. 1968 Jan;48(1):1–64. doi: 10.1152/physrev.1968.48.1.1. [DOI] [PubMed] [Google Scholar]
- Decaro T. F. Correlation between kinetically defined calcium compartments and contractile response in rabbit atrium. Nature. 1967 Sep 9;215(5106):1182–1183. doi: 10.1038/2151182a0. [DOI] [PubMed] [Google Scholar]
- LANGER G. A., BRADY A. J. Calcium flux in the mammalian ventricular myocardium. J Gen Physiol. 1963 Mar;46:703–719. doi: 10.1085/jgp.46.4.703. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LANGER G. A. KINETIC STUDIES OF CALCIUM DISTRIBUTION IN VENTRICULAR MUSCLE OF THE DOG. Circ Res. 1964 Nov;15:393–405. doi: 10.1161/01.res.15.5.393. [DOI] [PubMed] [Google Scholar]
- Ringer S. A further Contribution regarding the influence of the different Constituents of the Blood on the Contraction of the Heart. J Physiol. 1883 Jan;4(1):29–42.3. doi: 10.1113/jphysiol.1883.sp000120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Teiger D. G., Farah A. Calcium movements in resting and stimulated isolated rabbit atria. J Pharmacol Exp Ther. 1967 Jul;157(1):8–18. [PubMed] [Google Scholar]