Myocardial metabolism and function in acutely ischemic and hypoxemic isolated rat hearts

M. Samaja, R. Motterlini, S. Allibardi, S. Casalini, G. Merati, A. Corno, S. Chierchia

Research output: Contribution to journalArticle

Abstract

We tested the hypothesis that residual oxygen supply during acute low-flow ischaemia or hypoxemia is a major regulator of myocardial performance, metabolism and recovery. Rat hearts were exposed for 20 min to either ischemia (coronary flow reduced to 10% of baseline), hypoxemia (oxygen content reduced to 10% baseline) or a "mixed" condition (combined ischaemia and hypoxemia). The oxygen supply (coronary flow × oxygen content) was matched in all groups (n = 16 per group). Hypoxemic hearts had the highest performance (systolic and developed pressures, ±dP dtmax and oxygen uptake) and content of IMP and AMP. Ischaemic hearts had the highest content of ATP, phosphocreatine, adenine nucleotides and purines. As flow and/or oxygenation were restored, post-ischemic hearts showed better functional and metabolic recovery than post-hypoxemic ones. "Mixed" hearts were more similar to hypoxemic ones during oxygen shortage but to ischemic ones during recovery. We conclude that as oxygenation is critically limiting, coronary flow is relatively more important than oxygen supply in determining myocardial function, metabolism and recovery, most likely secondary to changes in the metabolism of diffusible substances.

Original languageEnglish
Pages (from-to)1213-1218
Number of pages6
JournalJournal of Molecular and Cellular Cardiology
Volume27
Issue number5
Publication statusPublished - May 1995

Keywords

  • Adenine nucleotides
  • ATP
  • Hypoxemia
  • Ischemia
  • Metabolism
  • Phosphocreatine
  • Recovery

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Molecular Biology

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    Samaja, M., Motterlini, R., Allibardi, S., Casalini, S., Merati, G., Corno, A., & Chierchia, S. (1995). Myocardial metabolism and function in acutely ischemic and hypoxemic isolated rat hearts. Journal of Molecular and Cellular Cardiology, 27(5), 1213-1218.