Pflügers Archiv

, Volume 410, Issue 1, pp 23–29

On the mechanism of histamine induced enhancement of the cardiac Ca2+ current

  • J. Hescheler
  • M. Tang
  • B. Jastorff
  • W. Trautwein
Excitable Tissues and Central Nervous Physiology

DOI: 10.1007/BF00581891

Cite this article as:
Hescheler, J., Tang, M., Jastorff, B. et al. Pflugers Arch. (1987) 410: 23. doi:10.1007/BF00581891

Abstract

In guinea pig ventricular myocytes, the effect of histamine on the slow Ca2+ current (ICa) was studied and the following results were obtained: (1) Superfusion of cells with histamine resulted in a dose-dependent enhancement of the amplitude of ICa. The threshold concentration of histamine was 10−8 M, half maximal increase occurred at 3×10−7 M and maximal enhancement (about 3–4-fold) at 5×10−6 M. (2) The histamine effect was greatly reduced by the H2 antagonist cimetidine (10−5 M) but only slightly by the H1 antagonist diphenhydramine (10−5M). (3) Effects of isoprenaline (ISP) and histamine at maximal effective concentrations on ICa were not additive, suggesting that both agents use the same intracellular pathway. Intracellular infusion of a blocker of the cAMP-dependent protein kinase, Rp-cAMPS (10−4 M), prevented the histamine effect. (4) The involvement of GTP-dependent transducer proteins was studied by cell dialysis with several GTP derivatives. Intracellular application of the stable GDP-analogue, GDP-β-S, reduced the histamine effect on ICa, whereas the stable GTP analogue, GTP-γ-S, mimicked the histamine effect.

Key words

Histamine Ventricular myocytes Cacurrent cAMP-analogue GTP-analogues 

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • J. Hescheler
    • 1
  • M. Tang
    • 1
  • B. Jastorff
    • 2
  • W. Trautwein
    • 1
  1. 1.II. Physiologisches InstitutUniversität des SaarlandesHomburg/SaarFederal Republic of Germany
  2. 2.Fachbereich Biologie/ChemieUniversität BremenBremen 33Federal Republic of Germany