Effects of calcium channel blockers on stress protein synthesis in cardiac myocytes

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Updated: Aug 14, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
10:53

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents

Published on: July 3, 2013

I Löw-Friedrich1, W Schoeppe

  • 1Department of Nephrology, Hospital of Johann Wolfgang Goethe University, Frankfurt am Main, F.R.G.

Journal of Cardiovascular Pharmacology
|May 1, 1991
PubMed

Insights

Calcium channel blockers interfere with cellular stress responses in heart cells. These drugs can alter the production of specific stress proteins, impacting toxicity monitoring assays.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Cardiovascular Research

Background:

  • Stress proteins are biomarkers for cellular toxicity.
  • Cadmium chloride (CdCl2) and hydrogen peroxide (H2O2) induce specific stress protein synthesis in cardiac myocytes.
  • Stress protein detection monitors cellular toxicity.

Purpose of the Study:

  • To investigate the effect of calcium antagonists on stress protein synthesis in cultured mouse myocardial cells.
  • To determine if calcium channel blockers interfere with stress responses induced by toxins.

Main Methods:

  • Fetal mouse myocardial cells were exposed to toxins (CdCl2, H2O2) and calcium antagonists (diltiazem, verapamil, nifedipine).
  • De novo synthesis of stress proteins (30, 68, 70, 71 kDa) was analyzed.
  • Additive effects of sequential toxin exposure were documented.

Main Results:

  • CdCl2 induced 68, 71, and 30 kDa stress proteins; H2O2 induced a 30 kDa protein.
  • Sequential toxin exposure showed additive effects on stress protein synthesis.
  • Calcium antagonists (diltiazem, verapamil, nifedipine) at >0.05 mg/ml stimulated 30 kDa protein synthesis.
  • Calcium antagonists reduced CdCl2-induced 70 kDa stress protein synthesis.

Conclusions:

  • Calcium channel blockers interfere with stress protein formation in myocardial cells.
  • This interference may impact the use of stress proteins as toxicity biomarkers in the presence of these drugs.
  • Further research is needed to understand the mechanisms of this drug-cell interaction.

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