Interaction of ICa with INa/Ca2 [Ca++]i and Ca++ Binding Proteins in Frog Atrium: A Theoretical Study

  • R. L. Rasmusson
  • D. L. Campbell
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 311)


The sarcoplasmic reticulum (S-R) of cells from the atrium of the bullfrog (Rana catesbeiana) is not involved in the cyclic uptake and release of calcium under normal physiological conditions. Consequently, bullfrog atrial cells provide a system in which the interactions between the “L”-type calcium current (ICa), sodium-calcium exchange current (INa/Ca) and intracellular Ca++ binding proteins (calmodulin and two different classes of Ca++ binding sites on troponin: TCa, a calcium-specific binding site thought to be responsible for phasic tension generation, and TMg, a Ca++−Mg++ competitive binding site) may be examined in isolation from complications arising from S−R uptake and release. A Hodgkin and Huxley type model1 incorporating INa/Ca and intracellular Ca++ binding sites has been used to examine the potential interactions between these different mechanisms during the cardiac action potential.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Rasmusson, R.L., Clark, J.W., Giles, W.R., Robinson, K., Clark, R.B., Shibata, E.F., and Campbell, D.L., Am. J. Physiol., 259:H370–H389, (1990).PubMedGoogle Scholar
  2. 2.
    Doerr, T., Denger, R. and Trautwein, W., Pfluegers Arch. 413:599–603, (1989).CrossRefGoogle Scholar
  3. 3.
    Mazzanti, M. and DeFelice, L.J., Biophvs. J. 58:1059–1065, (1990).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1992

Authors and Affiliations

  • R. L. Rasmusson
    • 1
  • D. L. Campbell
    • 2
  1. 1.Departments of Biomedical EngineeringDuke UniversityDurhamUK
  2. 2.Departments of PharmacologyDuke UniversityDurhamUK

Personalised recommendations