Japanese Journal of Electrocardiology
Online ISSN : 1884-2437
Print ISSN : 0285-1660
ISSN-L : 0285-1660
Volume 5, Issue 7
Displaying 1-4 of 4 articles from this issue
  • DENIS NOBLE
    1985 Volume 5 Issue 7 Pages 940
    Published: September 10, 1985
    Released on J-STAGE: December 10, 2010
    JOURNAL FREE ACCESS
    Recent work has introduced two new techniques to cardiac electrophysiology:
    1. Isolation of single cardiac cells using enzymatic separation.
    This technique permits much faster and more reliable voltage clamp experiments to be perfomed.
    2. Patch recording of single ionic channels and of single cell ionic currents.
    These techniques have been used to show that the calcium current is activated and inactivated much more quickly than was shown by previous work on multicellular preparations. This leaves open the question what carries the slower components of inward current.
    It has been shown that there are three possible mechanisms:
    (i) There exists more than one type of calcium channel. Some channels may show slower kinetics.
    (ii) Intracellular calcium may activate current carried by the sodiumcalcium exchange process.
    (iii) Intracellular calcium may activate non-specific cation channels.
    Evidence will be presented for mechanisms (i) and (ii)
    These new results have been incorporated into a very extensive computer model: It will be shown that this model not only succeeds in reproducing normal electrical activity but is also capable of reproducing arrhythmias generated in the following circumstances:
    (a) Block of the Na-K pump by cardiac glycosides or by low K.
    (b) Stimulation with a current pulse during repolarization.
    (c) Low extracellular calcium concentrations.
    Download PDF (74K)
  • 1985 Volume 5 Issue 7 Pages 941-947
    Published: September 10, 1985
    Released on J-STAGE: September 09, 2010
    JOURNAL FREE ACCESS
    Download PDF (762K)
  • 1985 Volume 5 Issue 7 Pages 949-958
    Published: September 10, 1985
    Released on J-STAGE: September 09, 2010
    JOURNAL FREE ACCESS
    Download PDF (1162K)
  • 1985 Volume 5 Issue 7 Pages 959-1085
    Published: September 10, 1985
    Released on J-STAGE: September 09, 2010
    JOURNAL FREE ACCESS
    Download PDF (16034K)
feedback
Top