Skip to main content
NCBI home page
The Journal of General Physiology logoLink to The Journal of General Physiology
. 1971 Jul 1;58(1):71–93. doi: 10.1085/jgp.58.1.71

Studies of Cardiac Muscle with a High Permeability to Calcium Produced by Treatment with Ethylenediaminetetraacetic Acid

Saul Winegard 1
PMCID: PMC2226010  PMID: 4998356

Abstract

Thin strips of frog ventricle were isolated and bathed for 15 min in a solution containing 140 mM KCl, 5 mM Na2ATP, 3 mM EDTA, and 10 mM Tris buffer at pH 7.0. The muscle was then exposed to contracture solutions containing 140 mM KCl, 5 mM Na2ATP, 1 mM MgCl2, 10 mM Tris, 3 mM EGTA, and CaCl2 in amounts to produce concentrations of free calcium from 10-4.8 M to 10-9 M. The muscles developed some tension at approximately 10-8 M, and maximum tension was achieved in 10-5 M Ca++. They relaxed in Ca++ concentrations less than 10-8 M. The development of tension by the EDTA-treated muscles was normalized by comparison with twitch tension at a stimulation rate of 9 per min before exposure to EDTA. In 10-5 M Ca++ tension was always several times the twitch tension and was greater than the contracture tension of a frog ventricular strip in KCl low Na-Ringer. Tension equal to half-maximum was produced at approximately 10-6.2 M Ca++. Intracellular recording of membrane potential indicated that after EDTA treatment the resting potential of cells in Ringer solution with 10-5 M Ca or less was between 5 and 20 mv. Contracture solutions did not produce tension without prior treatment with EDTA. The high permeability of the membrane produced by EDTA was reversed and the normal resting and action potentials restored in 1 mM Ca-Ringer. Similar studies of EDTA-treated rabbit right ventricular papillary muscle produced a similar tension vs. Ca++ concentration relation, and the high permeability state reversed with exposure to normal Krebs solution.

Full Text

The Full Text of this article is available as a PDF (1.4 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BRIERLEY G. P., MURER E., BACHMANN E. STUDIES ON ION TRANSPORT. III. THE ACCUMULATION OF CALCIUM AND INORGANIC PHOSPHATE BY HEART MITOCHONDRIA. Arch Biochem Biophys. 1964 Apr;105:89–102. doi: 10.1016/0003-9861(64)90239-5. [DOI] [PubMed] [Google Scholar]
  2. CHANCE B. THE ENERGY-LINKED REACTION OF CALCIUM WITH MITOCHONDRIA. J Biol Chem. 1965 Jun;240:2729–2748. [PubMed] [Google Scholar]
  3. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Fawcett D. W., McNutt N. S. The ultrastructure of the cat myocardium. I. Ventricular papillary muscle. J Cell Biol. 1969 Jul;42(1):1–45. doi: 10.1083/jcb.42.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Garnier D., Rougier O., Gargouïl Y. M., Coraboeuf E. Analyse électrophysiologique du plateau des réponses myocardiques, mise en évidence d'un courant lent entrant en absence d'ions bivalents. Pflugers Arch. 1969;313(4):321–342. doi: 10.1007/BF00593957. [DOI] [PubMed] [Google Scholar]
  6. Hellam D. C., Podolsky R. J. Force measurements in skinned muscle fibres. J Physiol. 1969 Feb;200(3):807–819. doi: 10.1113/jphysiol.1969.sp008723. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Katz A. M. Contractile proteins of the heart. Physiol Rev. 1970 Jan;50(1):63–158. doi: 10.1152/physrev.1970.50.1.63. [DOI] [PubMed] [Google Scholar]
  8. Kushmerick M. J., Davies R. E. The role of phosphate compounds in thaw contraction and the mechanism of thaw rigor. Biochim Biophys Acta. 1968 Jan 15;153(1):279–287. doi: 10.1016/0005-2728(68)90170-9. [DOI] [PubMed] [Google Scholar]
  9. NIEDERGERKE R. The potassium chloride contracture of the heart and its modification by calcium. J Physiol. 1956 Dec 28;134(3):584–599. doi: 10.1113/jphysiol.1956.sp005667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Sommer J. R., Johnson E. A. Cardiac muscle. A comparative ultrastructural study with special reference to frog and chicken hearts. Z Zellforsch Mikrosk Anat. 1969;98(3):437–468. [PubMed] [Google Scholar]
  11. Staley N. A., Benson E. S. The ultrastructure of frog ventricular cardiac muscle and its relationship to mechanism of excitation-contraction coupling. J Cell Biol. 1968 Jul;38(1):99–114. doi: 10.1083/jcb.38.1.99. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. THOMAS L. J., Jr Increase of labeled calcium uptake in heart muscle during potassium lack contracture. J Gen Physiol. 1960 Jul;43:1193–1206. doi: 10.1085/jgp.43.6.1193. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. THOMAS L. J., Jr ouabain contracture of frog heart: Ca 45 movements and effect of EDTA. Am J Physiol. 1960 Jul;199:146–150. doi: 10.1152/ajplegacy.1960.199.1.146. [DOI] [PubMed] [Google Scholar]
  14. WEBER A., HERZ R. The binding of calcium to actomyosin systems in relation to their biological activity. J Biol Chem. 1963 Feb;238:599–605. [PubMed] [Google Scholar]
  15. Weber A. Parallel response of myofibrillar contraction and relaxation to four different nucleoside triphophates. J Gen Physiol. 1969 Jun;53(6):781–791. doi: 10.1085/jgp.53.6.781. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press

RESOURCES