Michael Samuel Dodd1,2, Helen J. Atherton1, Marie A. Schroeder1, Lisa C. Heather1, Lowri E. Cochlin1, Kieran Clarke1, George K. Radda1, Damian J. Tyler1
1Department of Physiology, Anatomy and Genetics, Oxford University, Oxford, Oxfordshire, United Kingdom; 2Department of Cardiovascular Medicine, Oxford University, Oxford, Oxfordshire, United Kingdom
The recent advent of hyperpolarized 13C-MRS has opened a new window on in vivo cardiac metabolism. The use of hyperpolarized [1-13C]pyruvate has previously been shown to provide an in vivo measure of pyruvate dehydrogenase (PDH) flux, which directly correlates with disease severity. The aim of this work was to compare in vivo measurements of PDH flux with ex vivo measurements of PDH enzymatic activity. Using well established mechanisms for modulating PDH activity, we have shown that in vivo PDH flux, as measured by hyperpolarized 13C MRS, significantly correlates with ex vivo PDH activity, as measured by well established biochemical assay.