Enhancing the [13C]bicarbonate signal in cardiac hyperpolarized [1-13C]pyruvate MRS studies by infusion of glucose, insulin and potassium
Article first published online: 24 JUN 2013
Copyright © 2013 John Wiley & Sons, Ltd.
NMR in Biomedicine
Volume 26, Issue 11, pages 1496–1500, November 2013
How to Cite
Lauritzen, M. H., Laustsen, C., Butt, S. A., Magnusson, P., Søgaard, L. V., Ardenkjær-Larsen, J. H. and Åkeson, P. (2013), Enhancing the [13C]bicarbonate signal in cardiac hyperpolarized [1-13C]pyruvate MRS studies by infusion of glucose, insulin and potassium. NMR Biomed., 26: 1496–1500. doi: 10.1002/nbm.2982
- Issue published online: 18 OCT 2013
- Article first published online: 24 JUN 2013
- Manuscript Accepted: 8 MAY 2013
- Manuscript Revised: 7 MAY 2013
- Manuscript Received: 17 JUL 2012
- cardiac metabolism;
- pyruvate dehydrogenase;
A change in myocardial metabolism is a known effect of several diseases. MRS with hyperpolarized 13C-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 [13C]bicarbonate signal in cardiac hyperpolarized [1-13C]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 [1-13C]pyruvate. No [13C]bicarbonate signal could be detected in the fasted state. However, a significant increase in the [13C]bicarbonate signal was observed by the infusion of a high dose of GIK. This study demonstrates that a high [13C]bicarbonate signal can be achieved by GIK infusion in fasted rats. The increased [13C]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.