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ATP gated potassium channels in acute myocardial hibernation and reperfusion

J Offstad1, K A Kirkebøen, A Ilebekk

  • 1Institute for Experimental Medical Research, Ullevål Hospital, Oslo, Norway.

Cardiovascular Research
|June 1, 1994
PubMed

Insights

Opening ATP-gated potassium (KATP) channels and stimulating adenosine receptors are vital for regulating coronary blood flow. This study found KATP channels do not influence perfusion-contraction matching or recovery after reperfusion in piglet and rabbit hearts.

Area of Science:

  • Cardiovascular Physiology
  • Cardiac Metabolism
  • Pharmacology

Background:

  • ATP-gated potassium (KATP) channels and adenosine play critical roles in regulating coronary blood flow.
  • Activation of KATP channels and adenosine receptor stimulation offer protection against myocardial infarction and stunning.

Purpose of the Study:

  • To investigate the involvement of KATP channels and adenosine receptors in perfusion-contraction matching.
  • To determine the role of KATP channels and adenosine receptors in acute myocardial hibernation.
  • To assess the impact of KATP channels and adenosine receptors on functional recovery after reperfusion.

Main Methods:

  • Isolated piglet and rabbit hearts were perfused with modified Krebs Henseleit solutions.
  • The effects of KATP channel opener (aprikalim) and antagonist (glibenclamide), and adenosine receptor antagonist (SPT) were examined during low-flow ischemia and reperfusion.
  • Measurements included perfusion pressure and left ventricular systolic pressure.

Main Results:

  • KATP channel modulation significantly altered coronary vascular tone in both piglet and rabbit hearts.
  • Left ventricular systolic pressure decreased in parallel with coronary flow reductions across all treatment groups.
  • Functional recovery after reperfusion was not significantly modulated by KATP channel activity or adenosine receptor blockade.

Conclusions:

  • Coronary vascular tone is highly sensitive to KATP channel modulation and adenosine receptor blockade.
  • KATP channels do not appear to play a role in perfusion-contraction matching, acute hibernation, or functional recovery during reperfusion in these models.
  • Adenosine receptor antagonism also did not affect these functional parameters in piglet hearts.
Abstract

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