PMID: 934352Jan 14, 1976Paper

Effect of theophylline on calcium exchangeability in ventricular myocardium

Naunyn-Schmiedeberg's Archives of Pharmacology
P Bellemann, H Scholz


The effects of theophylline on contractile force and myocardial calcium exchangeability were studied in isolated, electrically driven Langendorff perfused guinea-pig hearts. Following a 30-min exposure to 45Ca, total cellular calcium and 45Ca activity were measured in right ventricular samples. "Nontoxic" theophylline concentrations (5 x 10(-5) -10(-3) g/ml) which augmented contractile force without producing arrhythmias or contractures had no effect on total tissue calcium and did not alter the size of the fraction of cellular calcium exchangeable under steady-state conditions. A "toxic" concentration of theophylline (2 x 10(-3) g/ml) induced contractures and increased the amount of exchangeable cellular calcium. The latter effect was due to an increase in total calcium; the unlabelled cellular calcium fraction remained unchanged under the influence of all theophylline concentrations studied. The results suggest that theophylline increases the steady-state calcium exchangeability in ventricular myocardium only when the total calcium concentration is also increased.


Feb 15, 1970·The Japanese Journal of Physiology·M Taniguchi, T Nagai
Oct 1, 1969·Circulation Research·P J PretoriusG Inesi
Nov 1, 1970·The Journal of Pharmacy and Pharmacology·P R Beckett
Oct 1, 1974·British Journal of Pharmacology·P Bellemann, H Scholz
Jul 1, 1969·The Journal of Cell Biology·D W Fawcett, N S McNutt
Feb 1, 1970·The American Journal of Cardiology·J R Sommer, E A Johnson
Dec 1, 1971·Journal of Molecular and Cellular Cardiology·K I Shine, G A Langer
Jul 1, 1969·The Journal of Cell Biology·N S McNutt, D W Fawcett
Jan 1, 1969·Pflügers Archiv : European journal of physiology·H G Glitsch


Apr 1, 1983·Proceedings of the National Academy of Sciences of the United States of America·P BellemannR Towart
Nov 1, 1982·Progress in Cardiovascular Diseases·J Ferlinz

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