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Enhancing the [ 13 C]bicarbonate signal in cardiac hyperpolarized [1‐ 13 C]pyruvate MRS studies by infusion of glucose, insulin and potassium
Author(s) -
Lauritzen Mette Hauge,
Laustsen Christoffer,
Butt Sadia Asghar,
Magnusson Peter,
Søgaard Lise Vejby,
ArdenkjærLarsen Jan Henrik,
Åkeson Per
Publication year - 2013
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.2982
Subject(s) - bicarbonate , citric acid cycle , pyruvate dehydrogenase complex , chemistry , medicine , pyruvic acid , endocrinology , insulin , pyruvate decarboxylation , metabolism , sodium bicarbonate , citric acid , biochemistry , enzyme
A change in myocardial metabolism is a known effect of several diseases. MRS with hyperpolarized 13 C‐labelled pyruvate is a technique capable of detecting changes in myocardial pyruvate metabolism, and has proven to be useful for the evaluation of myocardial ischaemia in vivo . However, during fasting, the myocardial glucose oxidation is low and the fatty acid oxidation (β‐oxidation) is high, which complicates the interpretation of pyruvate metabolism with the technique. The aim of this study was to investigate whether the infusion of glucose, insulin and potassium (GIK) could increase the myocardial glucose oxidation in the citric acid cycle, reflected as an increase in the [ 13 C]bicarbonate signal in cardiac hyperpolarized [1‐ 13 C]pyruvate MRS measurements in fasted rats. Two groups of rats were infused with two different doses of GIK and investigated by MRS after injection of hyperpolarized [1‐ 13 C]pyruvate. No [ 13 C]bicarbonate signal could be detected in the fasted state. However, a significant increase in the [ 13 C]bicarbonate signal was observed by the infusion of a high dose of GIK. This study demonstrates that a high [ 13 C]bicarbonate signal can be achieved by GIK infusion in fasted rats. The increased [ 13 C]bicarbonate signal indicates an increased flux of pyruvate through the pyruvate dehydrogenase enzyme complex and an increase in myocardial glucose oxidation through the citric acid cycle. Copyright © 2013 John Wiley & Sons, Ltd.