Adenosine prevents cardioplegia-induced Ca2+ loading in cardiac cells

A. Jovanovic, A. Alexeey, J. López, W. Shen, A. Terzic

Research output: Contribution to journalArticle

Abstract

Hyperkalemic cardioplegia is used to arrest the heart during open heart surgery by depolarizing the sarcolemma. A recognized adverse effect of hyperkalemic cardioplegia is ventricular dysfunction related to intracellular Ca2+ loading, but no effective means of protection under these conditions have been established. Whether adenosine, a known cardioprotective agent, could prevent intracellular Ca2+ loading without altering cardioplegia-induced depolarization was investigated using epifluorescent and laser confocal microscopy, and perforated patch-clamp electrophysiology. In ventricular myocytes isolated from guinea pig hearts, and loaded with a Ca2+-sensitive fluorescent probe, exposure of myocytes to 16 mM K+ induced intracellular Ca2+ loading, and membrane depolarization. Yet, adenosine (1 mM) effectively prevented Ca2+ loading whithout reducing the magnitude of cardioplegia-induced depolarization. The preventing effect of adenosine on Ca2+ loading was antagonized by inhibitors of protein kinase C. Adenosine did slow the rate of K+-induced membrane depolarization which could be repsonsible for a decrease in net Ca2+ influx. The property of adenosine to prevent hyperkalemia-induced Ca2+ loading may contribute to the cytoprotective efficacy of this agent as an adjunct to conventional hyperkalemic cardioplegia used in cardiac surgery.

Original languageEnglish (US)
Pages (from-to)163
Number of pages1
JournalClinical Pharmacology and Therapeutics
Volume61
Issue number2
StatePublished - 1997
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Pharmacology

Cite this

Jovanovic, A., Alexeey, A., López, J., Shen, W., & Terzic, A. (1997). Adenosine prevents cardioplegia-induced Ca2+ loading in cardiac cells. Clinical Pharmacology and Therapeutics, 61(2), 163.