Cytosolic Ca2+ domain-dependent protective action of adenosine in cardiomyocytes

Aleksandar Jovanovic, Jose R. Lopez, Andre Terzic

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Recently, in beating cardiac cells heterogeneous spatiotemporal patterns in cytosolic Ca2+ distribution have been visualized, and associated with cell contraction. In non-beating cardiomyocytes, spatial heterogeneity of intracellular Ca2+ distribution has also been observed, yet its functional implication in resting cardiac cells is not known. Herein, distinct domains of lower versus higher concentrations of cytosolic Ca2+ (0.17 and 0.37 μM, respectively) were observed using epifluorescent digital imaging in single, non-beating, fluo-3-loaded cardiomyocytes. Extracellular K+ (16 mM) induced a uniform increase of cytosolic Ca2+, despite the initial presence of distinct domains of cytosolic Ca2+ (from 0.17 to 1.82 μM in domains with lower, and from 0.37 to 2.03 μM in domains with higher Ca2+ concentration, respectively). In contrast, adenosine (1 mM) prevented extracellular K+ to induce cytosolic Ca2+ loading selectively within domains with lower (from 0.17 to 0.18 μM), but not in domains with higher (from 0.37 to 1.4 μM) basal Ca2+ concentration. Thus, the response of a cardiomyocyte to the protective action of adenosine is heterogeneous within a resting single cell. The domain-distinct cytoprotective action of adenosine appears to be set by the basal Ca2+ concentration within a cytosolic domain.

Original languageEnglish (US)
Pages (from-to)63-69
Number of pages7
JournalEuropean Journal of Pharmacology
Volume298
Issue number1
DOIs
StatePublished - Feb 29 1996
Externally publishedYes

Keywords

  • Adenosine
  • Ca domain
  • Ca, cytosolic
  • Cardioprotection
  • Fluo-3
  • Heart

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Pharmacology

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