Related Experiment Video

Updated: Aug 23, 2026

Murine Isolated Heart Model of Myocardial Stunning Associated with Cardioplegic Arrest
08:30

Murine Isolated Heart Model of Myocardial Stunning Associated with Cardioplegic Arrest

Published on: August 6, 2015

Cyclic GMP reduces myocardial stunning through non-cyclic GMP protein kinase mechanisms

Qihang Zhang1, Michael Lazar, Lin Yan

  • 1Department of Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, 08903, USA.

Journal of Cardiovascular Pharmacology
|July 10, 2004
PubMed

Insights

Myocardial stunning, a heart condition, was improved by cyclic GMP (cGMP). However, the protective effects of cGMP were not mediated by cGMP-dependent protein kinase.

Area of Science:

  • Cardiovascular Physiology
  • Molecular Cardiology

Background:

  • Myocardial stunning is a post-ischemic dysfunction.
  • Cyclic guanosine monophosphate (cGMP) plays a role in cardiac function.

Purpose of the Study:

  • To investigate if increased cyclic GMP and cGMP protein kinase activity can reduce myocardial stunning.
  • To explore the mechanisms by which cGMP affects myocardial stunning.

Main Methods:

  • Open-chest anesthetized dogs underwent left anterior descending coronary artery occlusion followed by reperfusion.
  • 8-Bromo-cGMP (8-Br-cGMP) was infused to increase cGMP levels.
  • Myocytes were isolated to assess the effects of 8-Br-cGMP and KT5823 (a cGMP protein kinase inhibitor).

Main Results:

  • 8-Br-cGMP administration reduced the time delay of regional shortening and restored regional work during systole in stunned hearts.
  • cGMP reduced myocyte shortening, while the cGMP protein kinase inhibitor KT5823 only restored myocyte shortening in control (non-stunned) conditions.
  • These findings suggest that the beneficial effects of cGMP on myocardial stunning may involve pathways independent of cGMP protein kinase.

Conclusions:

  • Regional myocardial stunning can be attenuated by elevated cyclic GMP levels.
  • The protective mechanisms of cyclic GMP against myocardial stunning appear to be independent of cGMP protein kinase activation.

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